A Margary number is the catalogue number given to a Roman road in Britain by the historian Ivan Margary. It lets different books and maps refer to the same road without confusion. Our map data does not carry Margary numbers.
Key takeaways
- Ivan Margary (1896 to 1976) devised the numbering system, and his book Roman Roads in Britain was his most influential work.
- A Margary number is a label for a road, so it stays the same however many names the road has had.
- Itiner-e built its British network mainly from Margary's recorded observations, but our data does not hold the numbers themselves.
- Britain is 11,574 km of road on our map, nearly all of it conjectured.
How Margary numbers work
By the mid twentieth century, Britain's Roman roads had many names and many authors, so it was easy to talk about the same road without knowing it. Ivan Margary, a British historian, fixed that by building a catalogue. Each road got its own number, so that it could be referred to without confusion and cross-referenced between different studies and writers [1].
Margary's most influential and complete work was Roman Roads in Britain (the third edition appeared in 1973) [1] [3]. Roads in Britain are often cited by their Margary number.
A Margary number is a label, not a measurement. It tells you which road is meant, not how certain its course is or how it was built.
How it connects to our data
Itiner-e used Margary's recorded observations as the main basis for Britain. The paper adds that further roads in the south-east Midlands came from another group, the Viatores, and that these two sources were digitised in an earlier project by Bishop. Some sections were then joined up with straight lines to make a connected network [2].
That means the lines you see in Britain trace back to Margary's work, but the Margary numbers did not come along. Our data does not carry them. If you have a Margary number, you will need to find the road by name or place, then compare it with a printed guide or local record.
An example from our data
The United Kingdom page shows 11,574 km of Roman road in 1,367 segments, with 377 Roman places matched. The Fosse Way is 372 km and Watling Street is 352 km. For each, the road page shows a name, length and certainty, but never a Margary number.
The United Kingdom is 98.8% conjectured in this data, and 0% certain.
The thing people get wrong
A Margary number is sometimes taken as proof that a road is Roman. It is a catalogue entry. Research goes on after any catalogue is printed: Wikipedia notes, for example, that the Roman origin of a famous stretch of stone road in the North York Moors is still under academic study [3]. Use the number to find the road, and use current research to judge it.
Frequently asked questions
Who was Ivan Margary?
A British historian (1896 to 1976) who became the leading authority on Roman roads in Britain. He is best remembered for the numbering system and for his book Roman Roads in Britain.
Can I search the map by Margary number?
No. Our data does not carry Margary numbers, so the search finds roads by name and place instead.
Do Margary numbers exist outside Britain?
The system was devised for roads in Great Britain. Other countries use their own catalogues.
Sources
- Ivan Margary, Wikipedia.
- Itiner-e: A high-resolution dataset of roads of the Roman Empire, Scientific Data (Brughmans et al., 2025).
- Roman roads in Britannia, Wikipedia.
- Every figure from our own map is worked out from the datasets on the data sources page (checked against Itiner-e version 2024 1.3).