I have been reading some of the threads on Roman Britain surviving the fall of the Western Empire and they all have certain things in common. The concensus seams to be that the withdrawl of central authority means that it would have been impossible to hold the British provences together. That with the withdrawl of the legions the Britons would be unable to defend themselves without hireing mercenaries and wouldn't be able to pay them anyway and that if a leader emerged with the ability to pull the remaining Romano British and Celtic peoples together he would enevitably attempet to use what forces he could rais to try for the Imperial Crown and abandon the island. I do have a sugestion to how the Romano Britons might have been able to hold back the tide of invaders but it begins 130 years before the withdrawl of the last legions. In the 280s the Admiral in command of the Channel Fleet with the support of the Legions in Britain had himself declared Emporer not of Rome but of Britannia and reigned for 2 years before being assasinated. He even issued his own coins which were of greater intrinsic value than the debased official coinage. My question his had Rome instead of killing him come to an agreement that recognised him as ruler of Britain would the 100+ years of him and his heirs as Emporer to the Romano British and High King to the native tribes have allowed them to build a society strong enough to survive the fall of the wester empire