When the Giambattista Nolli completed his monumental “Pianta Grande di Roma” (better known as the “Nolli Map”) in 1748, he was adding his name to a long list of extraordinary mapmakers of Rome that, throughout the long history of the city, labored to survey and depict Rome in all its topographical and architectural complexity.
More than fifteen centuries earlier, the “Forma Urbis Romae” made one of the first attempts, if not the first, to map the imperial city. Produced during the last years of Septimius Severus rule (203-211 CE,) it depicted floor plans of every building and monument within the central part of the city. It was gigantic: 60 feet wide by 45 feet high, carved on 150 marble slabs assembled on a wall of the Templum Pacis (now the church of Santi Cosma e Damiano) in the Imperial Fora.
By the Middle Ages, the Severan Plan had all but disappeared, turned into raw construction material. During the Renaissance, broken fragments of the marble slabs began to reappear and since the first discoveries in 1562, fragments have continued to emerge, most recently in 2001. Over the years, this extraordinary puzzle was the subject of several reconstructions. When the pieces were transferred to public ownership and moved to the Capitoline Museum in 1741, the museum curator Pietro Forrier undertook the first systematic project of assembly and exhibition of the map. With the assistance of--who else?--Giambattista Nolli.