At Ælfwald's death in 749, the kingdom was divided between Alberht and Beonna, who was perhaps a Mercian and who took the lead in issuing regnal coinage and maintaining a military alliance with Æthelbald, king of Mercia.
The evidence of Alberht's single discovered coin indicates that he had sufficient authority to issue his own coinage, a degree of independence that was soon eclipsed by the rapid growth of Offa's power in East Anglia.
A reference derived from tradition can be found in the annal for 749 in the Historia Regum, a mediaeval work possibly produced in part by Byrhtferth of Ramsey.
[8] Marion Archibald, a numismatist at the British Museum for 33 years, and the historian Dorothy Whitelock both asserted that the term Hunbeanna could be split into two separate names, Hun and Beonna.
The historian Barbara Yorke suggests the possibility that the kings each ruled a separate part of the kingdom at this time, but acknowledges that the political landscape of 749 is not well understood.
[24] According to the numismatists Philip Grierson and Mark Blackburn, the minting of coins in East Anglia probably began during the reign of Beonna.
A mint probably operated from Suffolk: coins continued to be produced through a period of Mercian hegemony and East Anglian independence, until the invasion by the Vikings in the second half of the ninth century.
[27] The confirmation of Alberht as a historical figure emerges from the discovery by controlled excavation of a single coin, considered to be unique, that can be attributed to him.