At the death of King Athelheard, his Cuthred became king. During the time of Athelheard much of Wessex had been lost to King Aethelbald of Mercia. Cuthred made it known he was not as weak a ruler as Athelheard and struggled against Aethelbald being his overlord. In the first three years of Cuthred's rule he warred with Mercia. In 743 Cuthred joined Aethelbald in fighting the Welsh. By all appearances this was a friendly alliance between the two kings. But the friendship soon ended. In 748 Cuthred's son, Cynric, tried to depose his father and died in the rebellion. According to the Anglo-Saxon Chronicle, the rebellion was encouraged by the Mercian king.