Frisii

The Frisii were an ancient tribe, who were neighbours of the Roman empire in the low-lying coastal region between the Rhine and the Ems rivers, in what what is now the northern Netherlands. They are not mentioned in Roman records after the third century, and archaeological records show that there was population decline, and frequent flooding caused by sea level rise. It is probable that many Frisii were among the early "Saxons" who settled in Britain. They are nevertheless also likely to be ancestors of the Frisians of today, whose material culture can be traced back to new settlements in the early Middle Ages.

Before the entry of the Romans into the area, settlers started to colonize the area in newly formed marshlands in the 6th or 5th centuries BC. As sea levels rose and flooding risks increased, the inhabitants learned to build their houses on village mounds or terps. The way of life and material culture of the Frisii hardly distinguished itself from the customs of the Chauci, east of the Ems.

During the 1st century BC, Romans took control of the Rhine delta but Frisii to the north of the river managed to maintain some level of independence. There was a lot of interaction, however, as the Frisii and Chauci were enlisted in the Roman army, and Roman traders established themselves north of the limes. There may have been Roman military outposts in Frisii territory. Some or all of the Frisii may have merged with Frankish and Saxon migrants in late Roman times, but they would retain a separate identity in Roman eyes until at least 296, when Frisian, Frankish and Chamavian groups were forcibly resettled as laeti. Archaeological findings suggest that they may have been transported to Flanders and Southeastern England.

The area where the original Frisii lived was largely deserted during the Migration Period, probably due to political instability and piracy, as well as climatic deterioration. When changing environmental and political conditions made the region attractive again it was repopulated in the 5th century by Anglo-Saxon settlers from Northwestern Germany and Southwestern Denmark, who adopted the old name Frisii. These new 'Frisians' lived in the coastal fringe stretching roughly from present-day Bruges to Bremen, including many of the smaller offshore islands. They incorporated the remainer of indigenous groups that lived in the area and successfully conquered what would become their new homelands. Medieval and later accounts of 'Frisians' refer to these 'new Frisians' rather than to the ancient Frisii.