12. How long did it take to dig the Hadrian’s Wall ditch?

Reconstruction work at Vindolanda suggested that it may have taken as long to dig the ditch, metre for metre, as it did to construct the curtain wall. Naturally, a key variable in trying to work out the length of time such an operation would take was the number of men devoted to it. As an example, with roughly 300 men from each of the three legions working on the ditch, it would take around fourteen months to complete the ditch.

Further reading: Birley 1977; Hill 2006