Germanic people who first appear in history after the beginning of the Christian era. The earliest mention of the Saxons is by the Egyptian mathematician and geographer Ptolemy in the 2d century ad, at which time they appear to have dwelt in the south Jutland Peninsula in the north of what is now Germany. They conducted piratical raids in the North Sea area, and in the 3d and 4th centuries they pressed southward into the region of the Weser River, where they encountered the Chauci and the Angrivarii, Germanic tribes that they subdued and absorbed. In the second half of the 4th century, the Saxons invaded Roman domains, and by the close of the 6th century all northwest Germany as far east as the Elbe River had become Saxon territory. In the 5th and 6th centuries, some groups of Saxons invaded Britain, where they were joined by other Germanic peoples, the Angles and the Jutes. At the beginning of the 7th century, the Anglo-Saxon conquest of Britain was practically completed. In the 8th century, the Frankish king Pepin the Short attacked the Saxons who remained in Germany. His son, Charlemagne, subdued them after a series of fierce wars lasting from 772 to 804 and forced them to accept Christianity. In the course of the 9th century, a great Saxon duchy came into existence under Frankish sovereignty, and its rulers established a dynasty of German kings in the 10th century. This old duchy of Saxony was dissolved toward the end of the 12th century, and the name of Saxony later passed over to an entirely different region.