A deep-rooted assumption in Anglo-Norman studies is that castles were imported into England in 1066, and that the Anglo-Saxon aristocracy had no tradition of constructing high-status towers at their residences. However, recent research into a class of free-standing stone tower-chapels, known as ‘tower-nave churches’, has concluded that many were built by high-ranking Anglo-Saxon lords at their residences for reasons of power, status and military advantage as well as the display of wealth and piety. Norman lords commonly occupied Anglo-Saxon lordly residences, and a number of lordly tower-nave churches were incorporated into early castles. New tower-nave churches were constructed at aristocratic residences both by Norman lords and Anglo-Saxons lords who had collaborated with the new regime. Significantly, this pre-existing tradition of Anglo-Saxon lordly towers also appears to have influenced the form of early Norman castle keeps. Whilst the great palatial keeps such as the Tower of London and Colchester were clearly direct copies of existing Norman-French practice, the more numerous class of local ‘tower-keeps’ built at aristocratic rather than royal castles appear to owe much of their form to Anglo-Saxon tower-nave churches. This chapter therefore argues that early Norman castles were not purely continental imports, but were significantly influenced by the existing towers of the Anglo-Saxon aristocracy.