The Severan Plan and an Introduction to Roman Topographical Studies

March 27, 2025

The Severan Plan and an Introduction to Roman Topographical Studies

Last night I spent 2 hours discussing the Severan Marble Plan (the Forma Urbis) and one of the fourth century CE regionary catalogues, the Notitia, with a group of students. This is the first of two blogs I am writing on the topics discussed. This blog will cover some background on the Forma Urbis and an historical outline of the discipline of Roman Topography. To some extent, the two are somewhat linked. The second blog, looking at the Notitia is here: Introducing the Notitia of the 14 Regions of the City to Students.

The Marble Plan

The Severan Marble Plan was constructed by the emperor Septimius Severus sometime between 203 and 211 CE in a room within the reconstructed Temple of Peace (it was destroyed in the fire of 192 CE). This room is thought to possibly have been the office of Rome’s urban prefect. The map itself was engraved on 150 marble slabs which had been placed previously on the wall and was then subsequently had the important lines painted in red. The map outlines the ground floor floor-plans of each building, and might have been based on land-tax (cadastral) maps held by the urban prefect. We know that the marble was placed before it was carved because the slabs were not uniformly thick, so the flat surface was presented for engraving.

The map could not have been viewed well from floor level (see David West Reynolds’ reconstruction below), so it could not have been a useful inclusion within the urban prefect’s office. So the map was about decoration, not directions. The map was a huge 18.1x13 metres and used a 1:240 scale.

David West Reynolds, 1997. “The Lost Architecture of Ancient Rome,” Expedition Magazine, vol. 39, p. 17.

Only 10-15% of the plan has been recovered, comprising 1,186 fragments. Each and every one of these have now been 3D scanned by a team at Stanford University. Their page also includes an excellent historical timeline of the map, including importantly its rediscovery in the 16th century which helped to invigorate the nascent study of Roman Topography. It can be read here midway down the page. In addition to these fragments, 87 were lost following their discovery and are only known through copies drawn which are now kept in the Vatican collection.

The other element that I think people have to remember when looking at the Marble plan is that it does not adhere to the modern standard North South axis. When you compare the how the Tiber appears on the slab map provided by Stanford University:

to a standard modern map of Ancient Rome (this one comes from Digital Maps of the Ancient World).

Having looked at modern maps for years before I ever heard of the Forma Urbis Romae, the need to realign my thinking to understand that an ancient Roman likely imagined the layout to their city completely differently to me was a little confronting.

The Discipline of Roman Topography

Most of the students had not been fully aware of Roman Topography as a sub-discipline of archaeology. It is best described as a multidisciplinary study area as it brings together literary studies, epigraphy, archaeology, architecture, spatial studies, manuscript studies, and cartography.

The development of the discipline can be seen through this timeline:

1551 - Leonardo Bufalini published a plan of Rome which included reconstructed plotting of ruins onto a contemporary map of Rome.*
1562 - discovery of fragments of the Forma Urbis.
1669 - Athanasius Kircher’s Latium, a flawed topographical study of the Lazio region.
1673 - Giovanni Pietro Bellori’s Fragmenta vestigii veteris Romae ex lapidibus Farnesianis. Please note that study used the fragments originally discovered which were claimed by the Farnese family and were used in one of their Roman gardens.
1680 - Raffaello Fabretti’s De Aquis et Aquaeductibus veteris Romae looks at the topography of ancient Latium.
1748 - Giambattista Nolli’s Pianta Grande di Roma (a map attempting to demarcate the 14 regions of Rome).*
1756 - Giovanni Battista Piranesi’s Le antichità romane (four volumes featuring engravings of Roman ruins). This tends to be of special interest to UQ students, as the wall near the door to the R. D. Milns Antiquities Museum on level 2 of the Michie Building features a huge reproduction of his engraving of the pyramid of Cestius.
1774 - Piranesi’s Pianta di Roma e del Campo Marzio (a map created for the tourist trade. To answer a question posed last night to which I did not have the answer, it measures 94 x 70.5 cm).*
1878-1927 - Rodolfo Lanciani, pioneer of the modern discipline of Roman topography was professor of Roman Topography at Università di Roma.
1893-1901 - Lanciani’s Forma Urbis Romae (sharing its title with the Marble Plan, it was made up of 46 detailed maps.*
* These items are included in the bibliography with links to view them for yourself if you wish.

Of course, the study of Roman topography has continued since then and I have included some pertinent works which will provide further information about just what this study results in. As someone who loves looking at literary sources, archaeological remains, inscriptions, maps, and manuscripts, I have a love for looking at the results of research in this area.