 The execution of an Anglo @-@ Saxon king on the orders of another ruler was very rare , although public hanging and beheading did occur at this time , as has been discovered at the Sutton Hoo site . Æthelberht 's death at the hands of the Mercians made the possibility of any peaceful union between the Anglian peoples ( including Mercia ) less likely than before . It led to Mercia 's domination of East Anglia , whose kings ruled over the kingdom for over three decades after Æthelberht 's death . 
