PONS AEMILIUS (previously named St.Maria Bridge, Senatorio Bridge, Broken Bridge).
In the beginning of Rome history there was just a single line of communication between the city and the Etruria: the road that, through the Sublicio bridge, crossed the Trastevere [beyond Tiber] plain near St. Cosimato and steep rise to the Gianicolo. The things improved in the VI century of Rome (II b.C.), when a new road, the present Lungaretta, and a new bridge were built.
The old "Pons Aemilius" was the first in stone on the Tiber (the Sublicio Bridge was wooden). It was erected in two steps: in 181-179 b.C. the censors Marco Emilio Lepido and Marco Fulvio Nobiliore raised the pillars that supported a wooden footbridge that, on 142 b.C., was replaced by four masonry arches by Publio Scipione Emiliano and Lucio Mummida.
Due to the obliquity of the Pons Aemilius with respect to the river flow axis, and the water pressure on the bridge in this curve point of the river, the bridge has been swept up at least four times.
The first flooding occurred during Probo age, about on 280 AD; the second one on 1230, when the bridge was again rebuilt by Gregorio IX. After an unsuccessful participation of Michelangelo (1548-49), continued by Nanni di Baccio Bigio (1551) a third flood occurred on 27 September 1557; the last reconstruction was by Matteo da Città di Castello on 1573-75 being pope Gregorio XIII (on the ruin remain a heraldic insignia of the Pope dragon); then it was used by Sisto V to support the Acqua Felice aqueduct to Trastevere; finally the 24 December 1598 flood definitively swept down the left bank arch that was no more rebuilt.
On 1853, being pope Pio IX, a French Company built an iron suspended footbridge, similar to the Fiorentini bridge one, in replacement of the previous unsafe wooden girders, in order to join the three remained arches of the bridge to the left bank.
According to the Canevari project for the arrangement of the Tiber banks the two arches at the right bank side were pulled down (1877) in order to erect downstream, very close to the only remained arch, the new Palatino Bridge (Angelo Vescovali, 1886-1891).
Through the centuries the bridge changed name several times: so it was called "St. Maria Bridge", "Senatorio Bridge" and now "Broken Bridge".