in Gallia Aquitania to the Visigoths in 418. Archaeology, however, has its limits, especially in dating. Although radiocarbon dating can provide a rough estimate, this is not accurate enough to associate archaeological finds with historical events. Dendrochronology is accurate enough to do this, though few suitable pieces of wood have been uncovered. Coins would normally be the most useful tool for dating, but not for sub-Roman Britain since no newly minted coins are believed to have entered circulation after the very early 5th century. There is archaeological evidence of Anglo-Saxons and Britons living on the same site. For example, in the cemetery at Wasperton, Warwickshire, one can see a family adopting Anglo-Saxon culture over a long period. End of Roman rule The proximate cause of the end of Roman rule in Britannia appears to have been a power-struggle between aristocrats and Stilicho, Roman general and strongman of the Roman Empire. In order to protect Italy from invasions by the Visigoths, Stilicho had seriously depleted the Roman forces defending the Limes Germanicus. In the summer of 406 there was a rebellion of legionarii in Britain that resulted in the acclamation of several usurpers in quick succession as imperator, a declaration of rebellion against the ruling emperor. The last of these, Constantine III crossed the Channel at Bononia and took with him all of the mobile troops left in Britain, thus denuding the province of any first line military protection. The Roman forces in Gaul (modern France) declared for him, followed by most of those in Hispania (modern Spain). On 31 December 406 the Vandals, Burgundians, Alans and Sueves crossed the Rhine and overran the Limes Germanicus. Meanwhile, there were barbarian raids on Britain in 408, but these seem to have been defeated. After 410 Honorius apparently sent letters to the cities of Britain telling them to fend for themselves, though this is sometimes disputed. The withdrawal of most Roman troops did not end the Roman culture of the "lost province", which still remained part of the Roman cultural world, with inhabitants who identified themselves as Roman. From the middle of the 5th century the Germanic raiders began to settle in the eastern river valleys. Later civil wars seem to have broken out, which have been interpreted either as being between pro-Roman and independence groups or between "Established Church" and Pelagian parties (Myres 1965, Morris 1965), a class struggle between peasants and