8. How long did it take to build Hadrian’s Wall?

Without detailed historical information to hand, any attempt to answer this question is dependent upon limited archaeological evidence and large amounts of guesswork. Nevertheless, it is known that work began under the governor A. Platorius Nepos, possibly soon after Hadrian’s visit in AD 122, and that the forts decision had been made before Nepos left office, some time before AD 127, since his name is recorded on inscriptions from the forts at Benwell and Halton Chesters. By the time Hadrian’s Wall was abandoned in favour of the Antonine Wall, around AD 140, the Turf Wall between Milecastles 49 and 80 had not only been completed but its replacement in stone had begun from Wall Miles 49 to 53 to the new narrow gauge.

Further reading: Breeze and Dobson 2000; Hill 2006