The Forma Urbis Romae or Severan Marble Plan is a massive marble map of ancient Rome, created under the emperor Septimius Severus between 203 and 211. Matteo Cadario gives specific years of 205–208, noting that the map was based on property records. It originally measured 18 m wide by 13 m high and was carved into 150 Proconnesian marble slabs mounted on an interior wall of the Temple of Peace. Created at a scale of approximately 1 to 240, the map was detailed enough to show the floor plans of nearly every temple, bath, and insula in the central Roman city. The boundaries of the plan were decided based on the available space on the marble, instead of by geographical or political borders as modern maps usually are. The map was oriented with south at the top. On the map are names and plans of public buildings, streets, and private homes. The creators used signs and details like columns and staircases. The Plan was gradually destroyed during the Middle Ages, with the marble stones being used as building materials or for making lime. In 1562, the young antiquarian sculptor Giovanni Antonio Dosio excavated fragments of the Forma Urbis from a site near the Church of SS. Cosma e Damiano, under the direction of the humanist condottiereTorquato Conti, who had purchased excavation rights from the canons of the church. Conti made a gift of the recovered fragments to Cardinal Alessandro Farnese, who entrusted them to his librarian Onofrio Panvinio and his antiquarian Fulvio Orsini. Little interest seems to have been elicited by the marble shards. In all about 10% of the original surface area of the plan has since been recovered, in the form of over one thousand marble fragments, which are kept in the Museo dell'Ara Pacis. Part of the excavated plan showed a portion of the Forum of Augustus, interpreted as "a working drawing or as a proof of the existence of a more ancient Forma Urbis."
Projects
Piecing together the surviving fragments of the plan is an activity that has engrossed scholars for centuries. Renaissance scholars managed to match and identify around 250 of the pieces, usually by recognizing famous landmarks such as the Colosseum and the Circus Maximus. In the second half of the 20th century, thanks to the works and publications of Guglielmo Gatti, Lucos Cozza, and Emilio Rodríguez Almeida, several fragments of the plan have been identified and located. Other scholars have re-interpreted the topography depicted on many fragments. A research project at Stanford University in 2002 had some success in positioning four fragments and in reassembling nine fragments with pattern recognition algorithms. Using archaeological and literary sources, since 1996 Pier Luigi Tucci has positioned twenty-four fragments in five Augustan regions and has offered new interpretations of the area of the AQVEDVCTIVM on the Caelian hill, of the Republican building in opus incertum at Testaccio, and of the area of the Circus Flaminius. A new piece of Forma Urbis Romae that completes the words "Circus Flaminius" was uncovered in 2014 at the Palazzo Maffei Marescotti, a building owned by the Vatican.
