The plate shows the outer side of the gate built in 1574 by Jacopo del Duca for Pope Gregory XIII. Its design is similar to the entrance to a villa.
Porta S. Giovanni replaced Porta Asinaria, a nearby ancient gate. The road shown in the plate was called in
the past Via Campana (because it was used to reach Campania, the region around Naples), while today it is called Via Appia Nuova.
The view is taken from the green dot in the small 1748 map here below. In the description below the plate Vasi made reference to: 1) Mola sulla marana (mill on a small stream of water); 2) Road leading to Via Latina. The small map shows also: 3) Porta S. Giovanni; 4) Porta Asinaria.
The view in June 2009 (it was taken from a slightly different position in order to show Porta Asinaria and Basilica di
S. Giovanni in Laterano after which the gate was named)
Quartiere Appio, one of the most populated new districts of Rome, lies immediately outside Porta S. Giovanni; thus
there is always a lot of traffic flowing into and out of Rome and six other openings were made in the walls to avoid back-ups.
The marana mentioned by Vasi does not exist any longer. It was an effect of the abandonment of the facilities built by the ancient Romans to control the flow of small urban streams. It entered the city near S. Sisto Vecchio and it crossed Circus Maximus making these areas very unhealthy.
(left) The gate; (right) detail of the inscription
Pope Sixtus V is usually regarded as having been the "town planner" of Papal Rome, however the process of opening new streets and improving communications between Rome and the other towns of the Papal State was started by his predecessor Pope Gregory XIII. When the gate was built and until the end of the XIXth century the neighbourhood inside the walls was very scarcely populated; most of the land was part of Villa Giustiniani Massimo.
When Emperor Aurelian surrounded Rome with new walls he did not plan for a gate at this location; there was only a posterula, a small opening for the farmers who lived outside the walls. This can explain its name: Asinaria (of the donkeys). It was only after the Lateran became the residence of the popes that a proper gate was built; this was done by Emperor Honorius in the frame of an overall improvement of the fortifications of Rome. Over the centuries it ended up with being at a lower level than the nearby area and for this reason it was eventually closed.
(left) Porta Metronia; (right-above) 1157 inscription; (right-below) the ancient "posterula"
Roman car drivers who live in Quartiere Appio know Porta Metronia very well, but the openings in the walls which they call Porta Metronia were made in the 1930s. The historical gate, a posterula, is partly below the current ground
level and only its arch is visible.
An inscription above the inner side of the gate sheds some light on a very obscure period of the history of Rome: "Anno MCLVII incarn(a)t(ionis) D(omi)ni n(ost)ri IHV (Iesu) XPI (Christi) S. P. Q. R. hec menia vetustate dilapsa restauravit senatores ..." followed by the names of ten Roman senators. In the middle of the XIIth century the authority of the pope was challenged by the attempts by the Romans to establish the independence of the city from both the Pope and the Emperor. In 1143 the ancient Roman Senate was revived (Renovatio Senatus) and in 1145 the pope (Lucius II) was killed by a stone thrown during a riot.
The Senators decided to celebrate the restoration of Porta Metronia by placing an inscription, something which had not been done for centuries. The inscription shows a total lack of skill, although the ancient monuments provided plenty of examples for it. Another interesting aspect is the absence of a reference to Adrian IV, the reigning pope (you may wish to see a similar inscription at Ponte Cestio).
A section of the walls near Porta Metronia
Excerpts from Giuseppe Vasi 1761 Itinerary related to this page:
Si vedono a destra le antiche mura di Roma, e la Porta della Cittą, che dalla vicina basilica si dice di s. Giovanni, dalla quale esce la via Campania, che ora conduce a Napoli. Si vedono di lontano antichissime rovine di acquedotti, parte rimessi in uso, e parte rimasti in abbandono.