Before he encountered the Belgic tribes in Britain, Julius Caesar had defeated their Gallic cousins in Gaul by 57BC, which comprised of a confederation of warlike tribes of what is today north-eastern France, these people had originally came from the Rhine, though, according to Caesar, they claimed to be Germanics, but they spoke the Celtic language and their chieftains had Celtic names, but they had a Teutonic inter-mixture in the warrior class.
The Belgic tribes crossed the Channel assisted by the fine seamanship of the Morini and the Menapii and seized a large part of southern England from the Brythonic tribes, overwhelmed by the numbers of in-coming groups of invaders from main-land Europe. A great sway of the southern counties came under the rule of the Belgic nobility. Farming methods rapidly improved for the ordinary man with heavy iron plows and better iron tools and grain was stored in numerous earthenware containers rather than the underground silos of the indigenous Brythonics.