Cynethryth is the only Anglo-Saxon queen consort to appear on coinage, and the only queen to appear on coinage in the early Medieval West. Cynethryth appears as a witness to charters and her image on her coins closely follows examples of coins of Roman Empresses. She was likely mother to the heir of Mercia, Ecgfrith, before she began to appear on coins. She was patroness to Chertsey Abbey was was recognized in letters as queen by Pope Adrian I.
After Offa’s death, Cynethryth became Abbess of Cookham and controlled the church at Bedford where Offa was buried, maintaining authority in religious circumstances, though she took no further part in politics. Her son, Ecgfrith, died after only 141 days on the throne, leaving Cynethryth without connections to the royal house of Mercia.