which may provide further evidence of Offa's scope as a ruler, though its attribution to his reign is disputed. A significant corpus of letters dates from the period, especially from Alcuin, an English deacon and scholar who spent over a decade at Charlemagne's court as one of his chief advisors, and corresponded with kings, nobles and ecclesiastics throughout England. These letters in particular reveal Offa's relations with the continent, as does his coinage, which was based on Carolingian examples. Ancestry and family Offa's ancestry is given in the Anglian collection, a set of genealogies that include lines of descent for four Mercian kings. All four lines descend from Pybba, who ruled Mercia early in the 7th century. Offa's line descends through Pybba's son Eowa and then through three more generations: Osmod, Eanwulf and Offa's father, Thingfrith. Æthelbald, who ruled Mercia for most of the forty years before Offa, was also descended from Eowa according to the genealogies: Offa's grandfather, Eanwulf, was Æthelbald's first cousin. Æthelbald granted land to Eanwulf in the territory of the Hwicce, and it is possible that Offa and Æthelbald were from the same branch of the family. In one charter Offa refers to Æthelbald as his kinsman, and Headbert, Æthelbald's brother, continued to witness charters after Offa rose to power. Offa's wife was Cynethryth, whose ancestry is unknown. The couple had a son, Ecgfrith, and at least three daughters: Ælfflæd, Eadburh and Æthelburh. It has been speculated that Æthelburh was the abbess who was a kinswoman of King Ealdred of the Hwicce, but there are other prominent women named Æthelburh during that period. Early reign, the midland territories and the Middle and East Saxons Æthelbald, who had ruled Mercia since 716, was assassinated in 757. According to a later continuation of Bede's Historia Ecclesiastica (written anonymously after Bede's death) the king was "treacherously murdered at night by his own bodyguards", though the reason why is unrecorded. Æthelbald was initially succeeded by Beornred, about whom little is known. The continuation of Bede comments that Beornred "ruled for a little while, and unhappily", and adds that "the same year, Offa, having put Beornred to flight, sought to gain the kingdom of the Mercians by bloodshed." It is possible that Offa did not gain the throne until 758, however, since a charter of 789 describes Offa as being in the thirty-first year of his reign. The conflict over the