The Franks formed one of several west Germanic tribes who entered the late Roman Empire from Frisia as foederati and established a lasting realm in an area that covers part of today's France and Germany (Franconia), forming the historic kernel of both these modern countries. The Frankish realm underwent many partitions and repartitions; since the Franks divided their property among surviving sons, and lacked a broad sense of a res publica, they conceived of the realm as a large amount of private property. This practice explains in part the difficulty of describing precisely the dates and physical boundaries of any of the Frankish kingdoms and who ruled the various sections. (more...)