this he probably imported workmen from Frankish Gaul. The cathedral and abbey in Canterbury, together with churches in Kent at Minster in Sheppey () and Reculver (669), and in Essex at the Chapel of St Peter-on-the-Wall at Bradwell-on-Sea, define the earliest type in southeast England. A simple nave without aisles provided the setting for the main altar; east of this a chancel arch separated the apse for use by the clergy. Flanking the apse and east end of the nave were side chambers serving as sacristies; further porticus might continue along the nave to provide for burials and other purposes. In Northumbria the early development of Christianity was influenced by the Irish mission, important churches being built in timber. Masonry churches became prominent from the late 7th century with the foundations of Wilfrid at Ripon and Hexham, and of Benedict Biscop at Monkwearmouth-Jarrow. These buildings had long naves and small rectangular chancels; porticus sometimes surrounded the naves. Elaborate crypts are a feature of Wilfrid's buildings. The best preserved early Northumbrian church is Escomb Church. From the mid-8th century to the mid-10th century, several important buildings survive. One group comprises the first known churches utilizing aisles: Brixworth, the most ambitious Anglo-Saxon church to survive largely intact; Wareham St Mary's; Cirencester; and the rebuilding of Canterbury Cathedral. These buildings may be compared with churches in the Carolingian Empire. Other lesser churches may be dated to the late eighth and early ninth centuries on the basis of their elaborate sculptured decoration and have simple naves with side porticus. The tower of Barnack hearkens to the West Saxon reconquest in the early 10th century, when decorative features that were to be characteristic of Late Anglo-Saxon architecture were already developed, such as narrow raised bands of stone (pilaster strips) to surround archways and to articulate wall surfaces, as at Barton-upon-Humber and Earls Barton. In plan, however, the churches remained essentially conservative. From the monastic revival of the second half of the tenth century, only a few documented buildings survive or have been excavated. Examples include the abbeys of Glastonbury; Old Minster, Winchester; Romsey; Cholsey; and Peterborough Cathedral. The majority of churches that have been described as Anglo-Saxon fall into the period between the late 10th century and the early 12th century. During this period, many settlements were first provided with stone churches, but timber also continued to be used; the best wood-framed church to survive