Last Updated: 05/23/2012

Spanning one-ninth of the earth's circumference across three continents, the Roman Empire ruled a quarter of humanity through complex networks of political power, military domination and economic exchange. These extensive connections were sustained by premodern transportation and communication technologies that relied on energy generated by human and animal bodies, winds, and currents.

Conventional maps that represent this world as it appears from space signally fail to capture the severe environmental constraints that governed the flows of people, goods and information. Cost, rather than distance, is the principal determinant of connectivity.

Example of map created by ORBIS
Example of map created by ORBIS
For the first time, ORBIS allows one to express Roman communication costs in terms of both time and expense. By simulating movement along the principal routes of the Roman road network, the main navigable rivers, and hundreds of sea routes in the Mediterranean, Black Sea and coastal Atlantic, this interactive model reconstructs the duration and financial cost of travel in antiquity.

Taking account of seasonal variation and accommodating a wide range of modes and means of transport, ORBIS reveals the true shape of the Roman world and provides a unique resource for our understanding of premodern history.


(a tutorial video can also be found here)

The interactive route map is the principal interface for the transportation model. To establish a historical route from one of the sites in our model to another, you select the start and destination sites from the two drop-down lists. Sites are named in accordance with The Barrington Atlas of the Greek and Roman World Routes differ depending on whether you are looking for the fastest, cheapest or shortest connection, on the modes and means (here called options) of transport, and on the month of the year.

Click "calculate route" to obtain cost information and a path for the route you have selected. Fastest routes are displayed in purple, cheapest routes in green, and shortest routes in yellow.
  • "Fastest" calculates the route that takes the least amount of time. Its path is highly dependent on the type of transportation you select. For example, faster land speeds may obviate the need for usually fast but often indirect sea travel.
  • "Cheapest" gives you the route with the lowest total cost priced in denarii (communes), a late Roman currency denomination used in the records from which we derive our price simulations. Price costs based on the modes and means of transport you choose. Transport of goods (exemplified by grain) and passenger travel incur different costs, and the price of grain transport on land varies depending on whether it is carried out by pack animals or wagons. As a result, there could be three different cheapest routes between two points.
  • "Shortest" only takes account of total distance, via the transportation network, from one point to another. The shortest route will often not be the fastest or cheapest one.

When you first access the map, all principal network modes are enabled by default. Disable individual modes as desired. Open sea and coastal sea routes operate 24 hours a day. Both of these modes must be enabled to access the complete maritime route network. Coastal sea routes and coastal sea (daytime) routes cannot be enabled at the same time. For travel on rivers, choose between a faster military boat and a slower civilian boat. A faster and a slower sailing option are available for sea travel. The interface offers a variety of road options: each of the speed options corresponds to a specific daily travel speed. Speed
external image using_02.pngoptions are only available for queries for fastest and shortest connections. Each of the price options corresponds to a specific expense for a cargo unit or passenger. Price options are only available for queries for cheapest connections.

If you want to find out how your route changes if you avoid travel by land, river, open sea or coastal sea lanes, deselect particular modes from this menu. For instance, if you only want to use coastal sea routes, simply uncheck the "Open sea" box. Note that unchecking boxes renders sites inaccessible if they can only be reached by the deselected modes of travel.external image route_response2.png

Cost results appear in the "Calculated route" box in the lower left-hand corner of the map. All results include the required days of travel (rounded to one decimal point) and the distance covered (in kilometers). Queries for routes that do not involve road travel generate prices based on sea and/or (civilian) river transport. Queries for routes that involve road travel generate prices that take account of all types of road travel for which specific historical price information is available, regardless of whether these are actually employed in the calculated route.

Tutorial Video

External Links