Since the Historia Brittonum says Penda ruled for only ten years (Bede says 22 years: 633–655), this may mean that it was dating Penda's reign from the time of his victory at Maserfield; this would make sense if Eowa's death removed an important rival to Penda, enabling him to claim or consolidate authority over all the Mercians.
Tendo en conta que a Historia Brittonum di que Penda reinou só dez anos (Beda di que foron 22: 633-655), isto podería significar que se data o reinado de Penda a partir da súa vitoria en Maserfield, o que tería sentido se a morte de Eowa liberase a Penda dun incómodo rival ao trono, permitíndolle reclamar ou consolidar a súa autoridade sobre toda Mercia.