Catterick in North Yorkshire had its military origins in around AD80, thereafter thriving as a town serving both a civilian and military population. This report on more than 40 years of excavation at the site documents the archaeology and history of Catterick and the nearby site of Bainesse. Details on the excavation, geophysical survey, aerial photographs and the analysis of pottery, brick, tiles and graffiti, provide an insight into the Romanisation of the town, the social and economic relationship between the civilian and military population and the transition to the medieval period. Part 2 will include the small finds: coins, metalwork, worked bone, glass, beads, wall plaster, human and animal bone.