Original: In the 5th century , during this period of historical silence , there is no doubt that many of the Frisians joined the migration of the Angles and Saxons who went through Frisian territory to invade Great Britain , while those who stayed on the continent expanded into the newly-emptied lands previously occupied by the Anglo-Saxons .
Simplified: In the 5th century , many of them joined the migration of the Anglo-Saxons who went through Frisian territory to invade Great Britain , while those who stayed in Europe moved into the newly-emptied lands previously lived in by the Anglo-Saxons .