Naumachia

Extensive water basin built by Augustus in *Trans Tiberim and dedicated in 2 B.C. to stage mock naval battles and aquatic displays for the Roman people. In the Res Gestae (23), Augustus gives the dimensions of this large basin as 1800 by 1200 Roman feet (533 x 355 m, and assuming a rectangular form, as has been done without exception), with a possible average depth of 1.5 m (Taylor 471). There was ‘an island in the middle’ of the basin, probably for distinguished spectators, and the island was connected to the bank by a bridge of notable span (Pliny, NH 16.190, 200). The useful life of the basin reached into the time of Titus (Dio Cass. 66.25.3); literary sources (including Augustus himself) imply that it was soon surrounded by the nemus Caesarum, the Grove of the Caesars (Suet., Aug. 43.1; or the Grove of Gaius and Lucius, Dio Cass. 66.25.3). According to Frontinus (Aq. 11.1-2: opus naumachiae), the main reason for the construction of the *Aqua Alsietina was to supply water for the Naumachia and the adjacent gardens in Trans Tiberim; its conduit ended behind the Naumachia (Frontin., Aq. 22.4: post naumachiam). A large conduit discovered on the slopes of the Ianiculum just above the monastery of S. Cosimato is considered the primary archaeological evidence for the location of the Naumachia, the Aqua Alsietina and the nemus Caesarum (RG 23, App. 2; Taylor 482-83; van Buren and Stevens; Lanciani, FUR pl. 33). Recently three scholars have commented in detail on the problems of the topographic location and shape of the Augustan Naumachia. Coarelli argued that the Naumachia was partly preserved on the Severan Marble Plan (Rodríguez Almeida, Forma pl. 20, frag. 28) as a large, blank, rectangular area, which was located by G. Gatti in the S Trans Tiberim (Coarelli 46-47, fig. 3; Gatti 94-95). This hypothesis locates the Naumachia between modern Viale del Trastevere and the ancient *Via Campana–Portuensis. Coleman supports Coarelli’s argument but suggests an elliptical plan for the basin for structural reasons and by comparison with similar structures (Coleman 52-53, fig. 1). However, in the most recent and comprehensive analysis of an impressive variety of evidence, Taylor returns to an earlier scholarly tradition and proposes an entirely different location for the Naumachia (Taylor). Highlighting the capacity of the Aqua Alsietina and its functional relationship with the Naumachia, as well as emphasizing the limited archaeological evidence, he not only proposes an hydraulic system for the basin, but also locates it in a rectangular form on the marshy lowlands of the Trans Tiberim, delimited to the N by the *Via Aurelia and at its SE corner by the Church of S. Francesco a Ripa, the findspot of impressive quantities of black and white mosaics at a depth of 8 m (Taylor 475-77, fig. 4). The suggested orientation of the Naumachia not only works well with the topographical contours of the area, but also coincides with the ancient street pattern (Rodríguez Almeida, Forma 140-43, pl. 44; frag. 37a), which was preserved through the mediaeval period (Taylor 479). If such a placement is correct, the Republican viaduct excavated in the Via Aurelia near S. Crisogono might well have acted as a discharge canal for the basin (Gatti; Taylor 481). Our map follows this convincing suggestion by Taylor. Surprisingly, numerous literary accounts witness the survival of the Naumachia, at least in part, down through the late 1st c. A.D., probably due in part to Augustus’ dedication of the surrounding honorific grove (Suet., Tit. 7.3; Dio Cass. 66.25.3). However, the vast area that it occupied must have been taken over by urban encroachment at the end of 1st c. A.D. (Taylor 482).