This is a detailed study of the archaeology of Roman Winchester-Venta Belgarum, a major town in the south of the province of Britannia- and its development from the regional (civitas) capital of the Iron Age people, the Belgae, who inhabited much of what is now central and southern Hampshire. The archaeology of the Winchester area in prehistory is considered, and so too is the later evidence from the town, between the end of organized Roman life shortly after 400 and the foundation, c.650, of the church later known as Old Minster. At the heart of this account is the publication of the relevant phases of the sites excavated in 1961-71 by the Winchester Excavations Committee, and of the finds recovered from these excavations. Volume 1 (Excavations) outlines previous work of relevance, and describes the WEC excavations and the post-excavation analysis of the discoveries, including full reports on the prehistoric, Roman, and post-Roman (to c.650) phases of the 14 sites excavated in 1961-71, with gazetteers for Roman Winchester, listing and describing all significant observations of the defences, and the streets and buildings within the walls. Volume 2 (Finds) presents about 4000 of the finds from the excavations of 1961-71, with additional significant objects from earlier excavations in Winchester or other Winchester collections. Finds are described and discussed by era and type, with coins and selected pottery followed by objects grouped by industry or purpose. Concordances list these finds by site and phase or by material.