The Frisian Kingdom (), also known as Magna Frisia, is a modern name for the post-Roman Frisian realm in Western Europe in the period when it was at its largest (650–734). This dominion was ruled by kings and emerged in the mid-7th century and probably ended with the Battle of the Boarn in 734 when the Frisians were defeated by the Frankish Empire. It lay mainly in what is now the Netherlands and – according to some 19th century authors – extended from the Zwin near Bruges in Belgium to the Weser in Germany. The center of power was the city of Utrecht. In medieval writings, the region is designated by the Latin term Frisia. There is a dispute among historians about the extent of this realm; There is no documentary evidence for the existence of a permanent central authority. Possibly, Frisia consisted of multiple petty kingdoms, which transformed in time of war to a unit to resist invading powers, and then headed by an elected leader, the primus inter pares. It is possible that Redbad established an administrative unit. Among the Frisians at that time, there was no feudal system. Pre-Migration Period The ancient Frisii were living in the low-lying region between the Zuiderzee and the River Ems. In the Germanic pre-Migration Period (i.e., before c. AD 300) the Frisii and the related Chauci, Saxons, and Angles inhabited the Continental European coast from the Zuyder Zee to south Jutland. All of these peoples shared a common material culture, and so cannot be defined archaeologically. What little is known of these early Frisii and their kings is provided by a few Roman accounts about two Frisian kings visiting Rome in the 1st century: Malorix and Verritus. It has been postulated that by AD 400 the Frisii abandoned the land and disappeared from archeological records. However, recent excavations in the dunes of Kennemerland show clear evidence of a continuous habitation. Migration Period Frisia suffered marine transgressions that made the land largely uninhabitable during the 3rd to 5th centuries. Whatever population may have remained dropped dramatically. In the 6th century, Frisia received an influx of new settlers, mostly Angles, Saxons, and Jutes, who would come to be known as "Frisians" even though they were not necessarily descended from the ancient Frisii. A legendary king of the Migration Period is Finn, associated with the Battle of Finnsburg. In the story, the young Danish