The first recorded act of Æthelred's reign is in 676, when his armies ravaged Kent, destroying Rochester, the seat of the bishops of West Kent. The reason for his attack is not recorded, but he may have wished to prevent King Hlothhere of Kent from regaining control of Surrey, which had been recently brought into the Mercian orbit by Wulfhere. It may also be that Æthelred sought revenge for the murder of the sons of Eormenred of Kent; the murders had been instigated by Ecgberht of Kent, Hlothhere's brother, and it is possible that Æthelred was the uncle of the murdered princes. A third suggestion is that the kings of Essex solicited the invasion, in response to recent Kentish attempts to gain dominance over the East Saxons. Regardless of the reason, Hlothhere was likely then forced to accept Æthelred's overlordship. The damage to the see of Rochester was so great that the incumbent bishop, Putta, retired from his diocese; his appointed successor, Cwichhelm, also gave up the see "because of its poverty".