North Frisia (; ; ) is the northernmost portion of Frisia, located in Schleswig-Holstein, Germany between the rivers Eider and Wiedau. It also includes the North Frisian Islands and Heligoland. The region is traditionally inhabited by the North Frisians. History Ancient settlements The geestland islands along the North Frisian coastline were already densely settled in the time of the early Roman Empire while the marshes further inland were not suited for settling. Only a few ancient marshland settlements have been found during archaeological excavations, namely in the modern area of southern Sylt, the Wiedingharde and along the southern Eiderstedt peninsula. With the beginning of the Migration Period, the number of settlements in North Frisia became ever lesser and many were totally abandoned. A new increase in population in the 8th century has been attributed to immigration but it is thought that the area had not been completely depopulated before. Medieval North Frisia The Frisians migrated to North Frisia from the South in two waves. During the 8th century A.D. they mostly settled on the islands Heligoland, Sylt, Föhr, Amrum and presumably also in parts of the Eiderstedt peninsula. The coastal marshlands of the mainland were settled in a second wave and after a series of storm surges the Frisians also used to settle on the higher inland geest, where Danes (Jutes) already lived. While the marshland and its bogs had to be drained, the higher geestland cores of the islands were in turn mostly barren and needed fertilisation before a proper agriculture could be established. During the Middle Ages, trade flourished between North Frisia and East Anglia, England. In particular, pottery was imported from the town of Ipswich and it has been suggested that relations between Frisians and East Anglians must have lasted for several centuries. In 1252, a united army of North Frisians from all territories between the Eiderstedt peninsula and the northern islands succeeded in defeating a Danish army led by king Abel. Salt making became a considerable trade in the 14th and 15th century when the North Frisians used saline peat as a resource. The salt trade coincided with an increase in international herring fishery off Heligoland. Treaties of 14th century farmers from Edoms Hundred with Hamburg based merchants and even the Counts of Flanders respectively have been preserved. The Frisian Uthlande region used to have its own jurisdiction, it was laid down for the first time