Pliny was sent by Trajan to the province of Bithynia and Pontus as legatus Augusti pro praetore consulari potestate, a charge he fulfilled from the 17^th September 110 CE to 112 CE. This appointment was exceptional because this province was a public one, and it was traditionally governed by a proconsul of praetorian standing. Slightly before Pliny’s nomination, the province of Bithynia and Pontus was temporarily made one of the emperor’s own provinces, meaning that Trajan was free to select whoever he wanted to send to this province to replace the usual proconsular governor (Hurlet, Le proconsul, p. 304). The choice of Pliny can be explained by the fact that the administration of Bithynia and Pontus had been largely neglected for many years, meaning that the cities of the province were affected by many irregularities. Trajan needed a man of confidence to regain control over the province.
Book X of Pliny’s letters is unique because a large number of its letters – except for the first fourteen – are part of the correspondence between Pliny, when he ruled the province of Bithynia and Pontus, and the emperor Trajan. It is actually the only collection of this kind that has been preserved. It thus gives important insight into the subjects that may have been frequently discussed between any proconsular governor (or similar) and the emperor (on this kind of correspondence see Hurlet, Le proconsul, p. 197-301). The letters of book 10 were published after Pliny’s death, and were probably not so carefully selected as in the case of the letters of books 1 to 9 of his correspondence (on this issue see Pliny the Younger, Letters X.6-7). The four letters presented here deal with the same case, the building of new baths at Prusia and the issue of the place where they could be built. However, the letters were written at two different moments: at the beginning of Pliny’s mission in Bithynia and Pontus for letters X.23-24 (between September and November 110 CE) and between January and September 111 CE for letters X.70-71 (Sherwin White, The Letters, p. 592, 657; Wynn, Pliny the Younger, p. 92, 121).

Prusa (modern Bursa) was a Greek city of South-Western Bithynia, and is mainly known for being the city of origin of the famous orator Dio Chrysostom. His speeches provide many details about the building policy in Prusa. They attest that ruins were part of the civic landscape (Dio, Speech XL.8-9; XLVII.15). They also show that, from c. 100 CE to 105 CE, the Prusan orator devoted himself to pleading for the modernisation of the city, a plan which provoked numerous hostile reactions among the inhabitants (see Fuhrmann, “Dio Chrysostom,” p. 166-170). This new building plan had been submitted to the ratification of the proconsul (Dio, Speech XL.5-6; XLV.15-16). The four letters of Pliny presented here precisely echo the requests made by some Prusians to increase the prestige of their city through a policy of urban renovation. However we see them from a different perspective, that of the legatus Augusti in charge of their province who relays them to the Roman emperor. There are many other situations of a similar kind in Pliny’s tenth book of correspondence. For instance, Pliny asked the authorisation of the emperor for the replacement of a defective aqueduct by a new one at Nicomedia (Ep. X.37.3), for the construction of a new aqueduct at Sinope (Ep. X.90.2) and for improving the sewage of the city of Amastris (Ep. X.98.2). In each case, it is reasserted or asked that cities have to be able to pay for the new constructions with their own resources. The fact that Pliny had to ask the emperor whether or not he authorized these new buildings shows that, in Prusa as probably in most Greek cities of the province, imperial authorisations were compulsory before any new building works could be undertaken (for the issue of asking for permission—X.23.1 quod videris mihi desiderio eorum indulgere posse, “it seems to me that you can assent to their petition”; X.70.3 si permiseris, “if you give me the permission”—, see Sherwin White, The Letters, p. 593). This preliminary imperial agreement can be explained by Trajan’s plan of restoring public order and financial balance in the cities of Bithynia and Pontus which often had financial difficulties (it seems to have been the case of Prusa, see Pliny, Ep. X.17.3).

The first exchange of letters between Pliny and the emperor did not solve the issue of the building of new baths at Prusa. Indeed, after Trajan’s response to Pliny that he authorized the construction only if it did not put a strain on the civic finances or if it did not lead to the introduction of a new tax, the case seems to have become more complex, especially after Pliny’s visit to Prusa. Actually, after Pliny came to supervise where the baths were supposed to be settled, he realised that the place chosen could be problematic. At that location, there was a ruined house that had been bequeathed, sixty years previously, to the emperor Claudius by a private individual, on the condition that a shrine to the Emperor should be built into the courtyard of the house. The legacy authorised the rental of the rest of the house – rent which was apparently collected by the civic institutions. However, we learn from Pliny’s letter that the whole building was destroyed because of looting and carelessness. In his response to Pliny, Trajan asks him about a point that he did not clarify, namely if the shrine dedicated to Claudius had been effectively built. If it had been actually the case, the consecrated area could not be used for the building of the baths without carrying out rituals of de-consecration (about the legal problems raised by the status of this building, see Wynn, Pliny the Younger, p. 121-122).

This group of letters is particularly interesting because it highlights the evolution of bathing culture and that of the constructions of public baths in the Roman East. Bathing culture was not specific to the Romans. Recent studies have considerably re-evaluated the number of Greek public baths (balaneia) and have have reassessed the fact these Greek baths were not simply “primitive predecessors” to the Roman ones (see Lucore and Trümper, Greek Baths, esp. catalogue p. 264-33). Having in mind this state of fact, the Roman conquests and their presence in the Eastern regions, and especially in Asia Minor, seem to have had three consequences on the use of public baths in urban contexts. The first one is the multiplication of the construction of public baths (especially of the bath-gymnasium complex) during the whole High-Empire, in many cities of the Roman East (about this phenomenon in Lycia, see Farrington, The Roman baths, p. 117-144). These constructions were made ex-nihilo or were the result of enlargements of the gymnasia built in the Classical or Hellenistic period, thanks to the addition of a bath-gymnasium complex (for a survey of the bath-gymnasium complexes in Asia Minor under the High Empire, see Yegül, Baths and Bathing, p. 250-313). The second major impact of the Roman presence was the fact that public baths became generally much bigger than the previous structures. The third consequence is related to the evolution of the bathing practice. Actually, with their huge pools and their numerous heated rooms dedicated to relaxation, Roman baths transformed bathing practice in the Roman East into something much more widespread and sophisticated (Trümper, “Introduction,” p. 1).
Concerning the specific case of Prusa during the High Empire, there were at least two thermal complexes in the city. One of them, usually called the “Royal Baths,” is located extra muros, at two kilometres west of the city. If the hot spring located here was probably already exploited during the Hellenistic period, we know, thanks to a speech of Dio Chrysostom dated from the 70s, that a building project was undertaken in its area at that time. Dio actually mentions that he ordered the construction of porticos – vowed for use as shops – nearby the “hot springs” (Dio, Speech XLVI.9, for the dating of the speech see Bekker-Nielsen, Urban Life, 177; Fuhrmann, “Dio Chrysostom,” p. 163; about this bath, see Fernoux, Notables et Élites, p. 378-379). The second bath known at Prusa is the one named as a balineum in these four letters exchanged between Pliny and Trajan. This bath was located inside the city and it replaced the old and dirty baths that may have dated from the Hellenistic period (see Fernoux, Notables et Élites, p. 379-380). The fact that Pliny mentions that he wanted to build a portico and an exedra implies that he planned to build a bath-gymnasia complex. The inhabitants of Prusa must have wanted to replace their old baths because they were antiquated. Moreover, having comfortable and wide baths was something essential for the prestige of any city of Asia Minor – as many of them were involved in intercity rivalries (Fagan, Bathing in Public, p. 166). Prusa, as most of the cities of Bithynia, was concerned by this phenomenon (about inter-rivalries in Bithynia, see Jones, The Roman World, p. 111). The situation of another city, that of Claudiopolis (modern Bolu), clearly echoes that of Prusia. In Ep. X.39.5, Pliny narrates that, at Claudiopolis, the citizens deliberately chose to replace their old Greek baths by a new one which had the advantage of being larger and which must have followed the standards of construction of baths which were usually followed in Asia Minor from the Roman conquest onwards.

Finally, it is interesting to question oneself on the ideological impact conveyed by such kind of building project. In various letters of Pliny to Trajan, the former explicitly associates the building activities and projects with praise of Trajan who is presented as a generous and exceptional emperor. This association appears in the two letters of Pliny given here: “Besides it is something [i.e. the construction of new baths at Prusa] that the prestige of the city and the splendour of your reign (saeculi tui nitor) require” (X.23.2); “through whose favour (beneficio) such a beautiful building, worthy of your name (dignumque nomine tuo), will be set up” (X.70.3) (in this perspective see also Ep. X.37.3; X.41.5; Wynn, Pliny the Younger, p. 92). It is a well-known fact that, from the perspective of the Roman power, constructions of public baths were operations which were underpinned and motivated by ideological motivations: these projects showed off the greatness and the generosity of Roman power (Fernoux, Notables et Élites, p. 259). If only few baths in south-west Asia Minor are attested as having been specifically dedicated to the emperor, the Roman authorities present in the province may have presented the new public baths as the perfect manifestation of the generosity of Roman authorities, but also of their capacity to provide a comfortable and civilized way of life. As Andrew Farrington writes: “The very forms of the architecture of bath buildings may have had their propagandistic side. Nothing like bath buildings, with their enormous ground areas und unprecedently wide vaults span had been seen before. They were open to interpretation as a concrete expression of the grandeur and ordered stability of the Roman empire…” (Farrington, The Roman baths, p. 136-137). The political dimension of public baths is made obvious in the case of the building project of Prusa as Pliny mentions that it will be dedicated to the emperor.

To conclude, for the inhabitants of many cities of Bithynia, as Prusa or Claudiopolis, to ask the Roman authorities for the right to build bath-complexes which were modelled on the standards used from the Roman conquest onwards, can be interpreted as a proof of the civilizational impact of Rome on that region and, more generally, on Asia Minor. These civic communities saw the advantage of adopting these new kinds of baths in terms of comfort, but also in terms of prestige because it enabled them to distinguish themselves from their neighbouring rival cities. The idea that baths were one of the most obvious manifestations of the civilizing impact of Rome on the Eastern provinces can also be found in a much later rabbinic source, Babylonian Talmud Shabbat 33a-b. In this text, one speaker first praises Rome for building markets, bath-houses and bridges. Another one criticizes the Romans for building these monuments for their own benefit. He thus enumerates that they build markets in which to put their prostitutes, bath-houses for their own enjoyment, or bridges to collect customs. Aside from the critical tone of this text, it is interesting to note that when the author(s) of this rabbinic text wanted to summarize the presence of Rome in the Eastern provinces, he/they chose three kinds of buildings that he/they thought to be the most representative of this presence. Baths were part of them.