Cardinal Stefan Wyszynski University

in Warsaw


Procuratores aquarum – the Guardians of Water or Crooks? The Procurators’ Activity in the Eyes of Frontinus*


ABSTRACT: Per la prima volta i procuratores aquarum furono nominati dall’imperatore Claudio. Furono impiegati inferiori, aiutanti dei curatores aquarum. Con loro i procuratores sorvegliarono la distribuzione dell’acqua pubblica nella città di Roma. Tuttavia Frontino nel suo trattato De aquaeductu urbis Romae di regola accusò i procuratores aquarum di truffe e diversi abusi, che commisero nel corso del mandato.



During the Principate, starting from the reign of Octavian Augustus, the custody over aqueducts and the distribution of water within the area of the city of Rome was exercised by the curatores aquarum. Since the emperor Claudius’ rule, they were supported by the procuratores aquarum. Frontinus described the circumstances of their nomination in his treatise, De aquaeductu urbis Romae.


Front., De aq. 105.2: Procuratores autem primus Ti. Claudius videtur admovisse, postquam Anionem Novum et Claudiam induxit.


As he put it, the offices were created on the initiative of Claudius after the Anio Novus and Aqua Claudia[1] aqueducts had been built, i.e. probably as early as in 52 AD[2]. However, there could be various reasons for the nomination of the first procurators. It seems probable that the construction of the above-mentioned water supply system could be one of them. As more and more aqueducts were built and the amount of water supplied to the city of Rome increased, there emerged a growing need for a group of people who would specialize in the distribution of water and control over the technical condition of the supply system.

A slightly different view is presented by Ch. Bruun[3]. The author is of the opinion that the office of procuratores aquarum was created as a result of establishing, also by Claudius, the familia Caesaris[4], the second division of aqueduct emergency service, the first being familia publica. He claims that procurators were intended to be chairmen of familia Caesaris.

Unfortunately, due to insufficient information on both familia Caesaris and procuratores aquarum it is not possible to definitely determine the relation between the two events. Additionally, Frontinus made it even more complicated to find arguments confirming the Bruun’s thesis. Although he mentioned the existence of a body that managed familia publica and familia Caesaris, he simply styled it as praepositor, i.e. a supervisor.


Front., De aq. 117.4: Tam amplum numerum utriusque familiae solitum ambitione aut neglegentia praepositorum in privata opera diduci revocare ad aliquam disciplinam et publica ministeria ita instituimus, ut pridie quid esset actura dictaremus et quid quoque die egisset actis comprehenderetur.


As stated in the fragment referred to above, both familiae were under the authority of supervisors whose role was to assign tasks and monitor their proper performance. Unfortunately, as regretted by Frontinus, slave workers who formed familiae, instead of carrying out tasks to the benefit of the public, were frequently used by praepositores for their own purposes that were in conflict with the interests of the general public (in privata opera diduci revocare).

It is probable that the cited fragment was also used by another researcher, R.H. Rodgers[5], who formulated a thesis that procuratores aquarum supervised familia publica and familia Caesaris. In the author’s opinion, it was the officer styled as praepositor[6]. He also believes that Frontinus might have intentionally described the officer he referred to in such an ambiguous manner. Malpractices of ambitio or neglegentia were typical of procuratores, vilici and even curatores[7]. Using such a general term, Frontinus could avoid allegations that he unjustly accused public officers of acts that compromised the interests of the public. It is therefore crucial to determine the features and principles of holding the office by the procurator aquarum. However, this topic should be addressed taking into consideration the time frame of the functioning of the office of procurators. It is important because a century after the introduction of the office it undergone significant organisational modifications that affected its character and function. The first period covers the times from establishing the office to the beginning of Trajan’s rule (98-117), and the second, the time of the rule of this and successive princeps.

From the very beginning, the office of procurator aquarum had an ancillary function in relation to curator aquarum.


Front., De aq. 2.1: Neque enim ullum omnis actus certius fundamentum crediderim, aut aliter quae facienda quaeque vitanda sint posse decerni, aliudve tam indecorum tolerabili viro, quam delegatum officium ex adiutorum agere praeceptis, quod fieri necesse est, quotiens imperitia praepositi ad illorum decurrit usum; quorum etsi necessariae partes sunt ad ministerium, tamen ut manus quaedam et instrumentum agentis.


The cited fragment starts with general comments about how officers should perform their duties. Only later did the author share his critical opinion about the work of individual officers who definitely included procuratores aquarum, although the term was not explicitly mentioned. Frontinus shared his opinion that there was no other stronger basis for any action or no other possibility to distinguish what should be done or avoided, as there was no greater dishonour to a rightful man than to exercise his powers according to the directions of his subordinates. However, such a situation was inevitable when the office was held by a person who lacked sufficient knowledge and thus had to rely on the experience of subordinates. Whereas, although participation of such subordinates in performing the function was necessary, they were only a kind of hand and a tool for the person who managed the fulfilment of the functions.

The first thought-provoking feature is the fact that procurators were mentioned at the very beginning of Frontinus’ De aquaeductu urbis Romae. Even though, at first it may seem that the author’s intent was to emphasize the role and significance of these officers, the tone of his expression and the manner he presented them indicate quite the opposite. The very construction of statements about procuratores raises questions. Noticeably, when referring to these officers, Frontinus avoided using their title. This approach was consistently kept by the author throughout his work. Summa summarum, the term procurator was used in only two cases in the entire report,– in the Front., De aq. 105.1-2 and Front., De aq. 112.3 fragments. In all other references, the officers were styled as praepositores or adiutores, depending on the context. The latter term was used in the discussed fragment Front., De aq. 2.1 with the meaning of assistants. It seems that Frontinus had a reason to apply this term to procurators. Probably, his main objective was to express criticism about the fact that he himself had to hold the office of curator aquarum not in cooperation with but at the direction of these lower-rank officers. Clearly, he was appalled by the fact that procurators, who were to provide assistance to curators, actually, took their place. Curators were not without the blame. They were higher rank officers who due to lack of knowledge subordinated themselves to lower rank officers, moreover, freedmen[8]. This gives rise to a question whether Frontinus actually had grounds to be so indignant about the activities of his predecessors, who held the office of curators for water affairs. Were they the only persons to be blamed for the situation or maybe there were also other factors that strengthened the position of procurators at the cost of their supervisors? In search for answers to these questions, the reasons and circumstances of establishing the office of procuratores aquarum should be considered. Apart from practical purposes of creating this position, as mentioned above, there was another, a strictly political motivation. Since the Augustus’ rule, the administration of public water was within the competences of curatores aquarum nominated by the princeps in agreement with the Senate[9]. This was a common practice until the times of Claudius who, in his endeavours to reinforce the emperor’s position as the central authority, attempted to reduce, as far as possible, the role of the Senate in the country. It was reflected in limiting the Senate’s influence on filling public positions and delegating such positions to emperor’s freedmen[10]. The newly established offices included procurator aquarum.

Thus, if as a result of the reforms introduced by Claudius, the role of the council of curatores aquarum was reduced in favour of procuratores and became almost dependant on them, it was obvious that Frontinus perceived them as a source of all evil and implicitly but fiercely criticised them. Unfortunately, his subjective opinion affects the reliability of the representation of these officers and hinders an accurate assessment of their activities[11].

Modifications to the personnel policy of the emperor’s administration initiated by Claudius are visible as early as during the rule of Vespasian. Beginning from 69, the character and nature of the emperor’s offices began to change, which was reflected in curator nominations for people from the equestrian class[12]. Although, these were rare cases at that time, such an approach clearly indicated the return to the model of the officers structure that included equites as initiated by Augustus. Such a policy was aimed at taking over the authority in the country from the representatives of the senators’ rank. The process of changes started by Vespasian was consistently continued by Domitian (81-96), however the final construction of the public administration relying on the knights’ rank was established by Trajan and his successors: Hadrian (117-138) and Antoninus Pius (138-161)[13].

Changes to the personnel policy in the emperor’s administration also affected the area of public waters management. However, they were introduced later in time, as the earliest records about the first equites holding the office of procurator aquarum come from the times of Trajan’s rule[14]. On the other hand, it is interesting that although this office became equestrian, emperor’s freedmen were not completely removed from power. The traces of their activity were preserved in the inscriptions made on the measuring nozzles (fistulae)[15] they supervised during Hadrian’s rule. Therefore, there are grounds to assume that from the second half of the 2nd century also this public function was monopolized by the equites[16]. The question is who held this office before that time. If, as mentioned above, starting from the rule of Vespasian, this function was assigned to equites, could it be possible that before that time the office had been held by two people, an eques and an emperor’s freedman concurrently? Was it possible that two people with such a distinct social background exercised one function? Did dignitas of an eques suffer due to his having a emperor’s freedman as his peer in this function. These concerns have generated controversies in the literature for a long time, and have even acquired its own term – “dual procuratorship”, “Pseudokollegialität” or collégialité inégale”[17].

There are two aspects that should be particularly considered in order to, at least to some extent, deal with the controversies and characterize the office of procurator aquarum. First, what was the purpose of creating an office of this kind. Second, what was a reasonable justification for the need of establishing an office that was so grossly disproportional in terms of the ranks’ discrepancy?

Some scholars are of the opinion that the disparity in the social background between the two officers is not so flagrant if it is assumed that a procurator-freedman was only an assistant to a procurator- eques. However, such an explanation is not fully satisfactory because it does not sufficiently explain the idea of establishing libertum Caesaris as a procurator for water affairs. Consequently, according to the studies conducted by Ch. Bruun[18], it may be presumed that the purpose of this solution was for a princeps to attain two goals. The first and most important from the perspective of the emperor’s policy was to ensure a long-term control over the activities of equites. Most likely, as already mentioned, from the times of Trajan, equites held the office of procurator on an exclusive basis. The second reason was to enhance the work of a procurator- eques to whom a emperor’s freeman was assigned as an assistant[19]. This kind of explanation is further supported by the fact that, as a rule, the emperor’s offices were one-person roles.

It is also difficult to determine a procurator aquarum term of the office. In the opinion of Ch. Bruun[20], it was up to two years. The author came to this conclusion based on calculations derived from inscriptions. Namely, he counted all the procurators whose names were recorded on the water pipes, and compared the number to the timeline of their terms of the office. According to his studies, between 83 and 96, under the rule of Domitian, the office was held by at least seven people, which would indicate that the term of the office for each of the procurators did not exceed two years.

The term of the office of procuratores aquarum is also related to the method of their nomination. First of all, considering the fact that they were emperor’s officers, it is highly probable that they were nominated. However, there are doubts about who nominated them. On the one side, since they were emperor’s officers, it would be reasonable that the only body authorized to nominate was the princeps. Nonetheless, in the modern literature it is claimed that it were curatores aquarum who nominated procurators[21]. This opinion seems well grounded, as procuratores were ancillary personnel to curators. Unfortunately, due to the lack of source texts, the reliability of this theory cannot be confirmed.

The final issue to be considered is the scope and nature of procuratores aquarum competences. The main source of information is, once again, the treatise De aquaeductu urbis Romae, although some data from the inscriptions is also helpful. Unfortunately, whereas Frontinus cannot be said to lack credibility in his descriptions of the system supplying water to Rome, his reluctance towards the office of the procurator gives raise to doubts about the reliability of his report. The author described the tasks, in particular, the manner of their execution by procurators in a very critical way due to the fact that he accused them of a series of unfair acts, which he believed they committed during and in relation to the performance of their functions. The examples of such criticism may be found in almost every fragment of his treatise reefing to procuratores:


Front., De aq. 105.4-5: Procurator calicem eius moduli, qui fuerit impetratus, adhibitis libratoribus signari cogitet, diligenter intendat mensurarum quas supra diximus modum et positionis notitiam habeat, ne sit in arbitrio libratorum, interdum maioris luminis, interdum minoris pro gratia personarum calicem probare. Sed nec statim ab hoc liberum subiciendi qualemcumque plumbeam fistulam permittatur arbitrium, verum eiusdem luminis quo calix signatus est per pedes quinquaginta, sicut senatus consulto  quod subiectum est cavetur.


In the above-mentioned fragment, Frontinus referred to the role of procuratores in the process of awarding the water licenses. The author explains that they exercised technical supervision over the use of public water. When an interested person brought a letter from the emperor to the curator confirming the awarded license, the curator appointed a procurator who was to perform the activity of connecting water to the licensee’s property. The procurator’s main duty was therefore to put stamps on public installations that supplied water to a particular entitled person. After that, the procurator was to control the exercise of rights by such a person[22]. Thus, every time a private person was granted a license, the procurator’s duty was to put a fistula marking with a size corresponding to the granted amount of water and to control the dimensions and location of individual nozzles. These were the tasks that frequently generated fraudulent behaviours of the procuratores. Frontinus described the substance of these activities in the following fragment of his treatise.


Front., De aq. 112.2-3: Ampliores quosdam calices quam impetrati errant positos in plerisque castellis inveni et ex iis aliquos ne signatos quidem. Quotiens autem signatus calix excedit legitimam mensuram ambitio procuratoris qui eum signavit detegitur.


As stated by the author, one of the most widespread abuses was the installation of incorrect connections to the pipes supplying water. Such an activity was unlawful because the pipes installed in the distribution nozzles (castella) were made of bronze (calices) and had a greater diameter than it was permitted under a granted license[23]. Frontinus called it a deceitful activity and put the blame on the pipe system keepers, i.e. aquarii, and their supervisors namely, procurators. His reasoning was that being the persons who marked every new fistula, they would have no difficulty in fixing nozzles in sizes different from required. As the water transfer installations were directly adjacent, they were able to fix and mark them as compliant fistulae but in fact, their diameters were greater than indicated in the license. Additionally, in some cases, the nozzles were not marked at all. This led to an increase in both the amount of water used illegally for private needs and the number of the recipients. Thus, it is difficult to argue with the main accusation formed by Frontinus against both aquarii and procurators that their acts were fraudulent and negligent.

There is also another reason why Frontinus would present the activities of procuratores aquarum with such criticism. Namely, he himself performed the duties of curator aquarum under the rule of Nerva, i.e. at the time when the office of procurator for water affairs was often held by equites. But, his criticism was addressed to procurators-freedmen. By presenting such a negative opinion about them, Frontinus might have intended to emphasize that it was a huge mistake to entrust this role to people representing this social class. Exposing their misconduct, he wanted to publicly express his disapproval of this model of the procurator aquarum office, and perhaps even warn against repeating the mistake that, as it turned out, caused damage to the country and its people.

If it is assumed that Frontinus’ words cited above from the fragments Front., De aq. 2.1 and 117.4 were addressed to procuratores, which is most probable, then there emerges another function of the officers. Namely, it is highly possible that they also dealt with financial aspects of the familia Caesaris activities. It should be remembered that procurators were a body that supervised and coordinated the works of this familia, and that was created solely on the initiative and at the expense of the ruler (fiscus Caesaris). The competences of procuratores aquarii probably involved deciding on the expenditures necessary to maintain familia Caesaris and perform its individual tasks[24].

Apart from the procuratores aquarum, there were also other procurators, including procuratores domicilii, who were responsible for hydraulic works in the city of Rome and also for the supply of public water. Such a conclusion may be drawn from the inscriptions preserved on individual elements of water installations, in particular, the measuring nozzles. As already mentioned, the duty of procuratores aquarii was to mark fistulae in order to confirm that it was legal. However, the inscriptions on the measuring nozzles both in and outside of Rome provide no indications that procuratores aquarii[25] were the only procurators competent in that respect. That is, most of the officers recorded on fistulae were simply styled as procuratores. In some cases, there are also inscriptions of procuratores domicilii. On the other hand, there are many inscriptions from the times of Hadrian and his successors that mention the procuratores patrimonii as the officers dealing with emperor’s land[26]. Only in some cases they were styled as procuratores aquarii[27]. Consequently, it could be assumed that there was an extensive group of ancillary officers who participated in the management of public water in Rome.

In all probability, procuratores aquarii were not the only officers who assisted in the management of and control over the municipal infrastructure during the Principate. It is believed that it was Claudius who nominated the first procurator Augusti ad ripam Tiberis responsible for the coordination and supervision of the works ordered by the princeps to construct the artificial port in Ostia[28]. Interestingly, this office probably existed only during the reign of Claudius. These facts confirm the thesis formulated at the beginning of this discussion, that procuratores aquarum were nominated for stricte political reasons rather than for the purpose of serving the City. In the records of, among others, Frontinus, procurators were presented as fraudulent and negligent officers who perceived their role only as an opportunity for quick and easy enrichment.




[Per la pubblicazione degli articoli della sezione “Tradizione Romana” si è applicato, in maniera rigorosa, il procedimento di peer review. Ogni articolo è stato valutato positivamente da due referees, che hanno operato con il sistema del double-blind]


* I would like to thank Mr Łukasz Wasilewski for his help with the translation of the article.


[1] Their construction started in 38 during the reign of the emperor Caligula however it was Claudius who completed them. Cf. Suet., Gaius 21; Suet., Claud. 20; Front., De aq. 13.1; CIL VI 1256. Both of the aqueducts were put into operation on the 1st of August 52 i.e. on the anniversary of Claudius’ date of birth. Cf. Front., De aq. 13.2; H.B. Evans, Water Distribution in Ancient Rome. The Evidence of Frontinus, Michigan 1994, 115; R.R. Benefiel, The Inscriptions of the Aqueducts of Rome: The Ancient Period, «The Waters of Rome» 1, 2001 http://www3.iath.virginia.edu/waters/Journal1BenefielNew.pdf .


[2] Although this date seems to be the most probable, the information about the first known name of the procurator aquarii is derived from inscriptions from the times of the emperor Nero. Cf. CIL XV 7271: Neronis Claudi Caesari Augusti, sub c(ura) Nesto(ris) Aug(usti) lib(erti) proc(uratoris).


[3] Ch. Bruun, The Water Supply of Ancient Rome. A Study of Roman Imperial Administration (Commentationes Humanarum Litterarum. 93), Helsinki 1991, 207. The relation between the two events i.e. the completion of Anio Novus and Aqua Claudia and the nomination of the first procuratores aquarii has also been noticed by L. Homo, Rome impériale et l’urbanisme dans l’antiquité, Paris 1951, 189, 193, and Ch. Bruun, ‘Medius fidius … tantam pecuniam Nicomedenses perdiderint’! Roman Water Supply, Public Administration, and Private Contractors, [w:] Tâches publiques et entreprise privée dans le monde romain, red. J.J. Aubert, Genève 2003, 310.


[4] Front., De aq. 116.2-4.


[5] R.H. Rodgers, Frontinus De aquaeductu urbis Romae, Cambridge 2004, 301.


[6] Whereas T. Ashby, The Aqueducts of Ancient Rome, Oxford 1935. 23 states that procuratores only managed the familia Caesaris.


[7] CIL VI 8495; 8496; E. De Ruggiero, Lo stato e le opere pubbliche in Roma antica, Torino 1925, 260-261; G. de Kleijn, The Water Supply of Ancient Rome. City Area, Water and Population, Amsterdam 2001, 109.


[8] C. Kunderewicz, O akweduktach miasta Rzymu. Frontinus, Warsaw 1961 (Prace Zakładu Archeologii Antycznej IHKM PAN, book 19), 77, item. 7. According to L. Homo, op. cit., 193 the reason why curators were subordinated to procurators could result from the fact that the latter had more expertise in practical aspects of the functioning of aqueducts because they continually dealt with it, and therefore were significantly more experienced than curators. 


[9] Ch. Bruun, Imperial Power, Legislation, and Water Management in the Roman Empire, «Insights» 3.10, 2010, 11; Tenże, Water Supply, Drainage and Water Supply. http://www.utsc.utoronto.ca/~kblouin/CLAD05H3_calendar_files/BruunWater.pdf; R. Kamińska, ‘Cura aquarumw prawie rzymskim, «Zeszyty Prawnicze» 10.2, 2010, 102.


[10] Th. Mommsen, Römisches Staatsrecht, (Graz 1952). II.2, 836-839, 1053; H.H. Scullard, From the Gracchi to Nero. A History of Rome from 133 B.C. to A.D. 68, London-New York 2007, 292.


[11] Cf. Ch. Bruun, The Water Supply…, 207.


[12] L. Homo, op. cit.,  193; Ch. Bruun, The Water Supply…, 219.


[13] E. De Ruggiero, Lo stato…, 136.


[14] K. Geißler, Die öffentliche Wasserversorgung im römischen Recht, Berlin 1998, 69; Ch. Bruun, Il funzionamento degli acquedotti romani, [in:] Roma imperiale. Una metropoli antica, red. E. Lo Cascio, Roma 2000, p. 148.


[15] CIL XV 7308; XV 7310.


[16] CIL XV, 7299; T. Ashby, op. cit., 23.


[17] H.G. Pflaum, s.v. Procurator, «RE» 23, 1957, col. 1278 ; Ch. Bruun, The Water Supply…, 220.


[18] Ch. Bruun, The Water Supply…, 220.


[19] Ch. Bruun, The Water Supply…, p. 217, who wrote: „The existence of colleagues in administrative sectors led by imperial freedmen and equestrian procurators is almost unheard of”.


[20] Ch. Bruun, The Water Supply…, . 216. On the other hand, according to K. Geißler, op. cit., p. 72, the term of the office of procurator aquarum was intended to be one year, but in fact it was sometimes prolonged to 20 years, which is confimed by the example of Alypiusa who held the office from 83/84 to 102 A.D. Compare: Iulianus, Epistulae et leges 404B.


[21] P. Fraccaro, s.v. acque, «EI» I, 1929, 368; O.F. Robinson, Ancient Rome. City Planning and Administration, London-New York 1992, 87.


[22] K. Geißler, op. cit., 74.


[23] The illegal activity of aquarii consisted in fixing calices that were 13.5% bigger or 20% smaller that they should be. As a result, the volume of water in the resservoire increased so that the supply system keepers could illegally supply water to other unauthorized persons. Such receipients of water were obliged to pay tax to aquarius instead of to the treasury. Cf. K. Geißler, op. cit., 203; J.G. Landels, Engineering in the Ancient World, Berkeley and Los Angeles 2000, 51-52; G. de Kleijn, op. cit., 107..


[24] M. Hainzmann, Untersuchungen zur Geschichte und Verwaltung der stadtrömischen Wasserleitungen, Wien 1975, 56; P.J. Aicher, Guide to the Aqueducts of Ancient Rome, Illinois 1995, 24.


[25] Ch. Bruun, Puzzles about Procurators in Rome, «Arctos» 39, 2005, 15, who is of the opinion that procuratores were assigned with different tasks related to the development of the capital’s infrastructure.


[26] CIL XV 7303: Imp(eratoris) Caes(aris) Nerv(i) Trai(ani) opt Aug(usti) Ger. Dac. Part. sub cura procurator(is) patrimoni(i) annae iucunda fec. Cf. CIL XV 7312: Imp(eratoris) Caes(aris) Trai(ani) Hadriani Aug(usti) sub cur(a) proc(uratoris) patri(monii). Cf. CIL XV 7739: Imp(eratoris) Caes(aris) Hadriani Aug(usti) sub cur(a) proc(uratoris) patri(monii). Cf. also Ch. Bruun, The Water Supply…, 221; C. Lo Cascio, Ilprinceps’ e il suo impero. Studi di storia amministrativa e finanziaria romana, Bari 2000, 131.


[27] CIL XI 3612; Ch. Bruun, The Water Supply…, 216.


[28] CIL XI 6337 = ILS 1422; CIGr. X 797; Plin., Nat. hist. 9.14; 16.202; Seut., Claud. 20; L. Homo, op. cit., 242; E. De Ruggiero, Lo stato..., 139.