By the time Oswiu died in 670 Wulfhere was the overlord of most of southern England. He installed Bishop Wine in London after he was expelled from Wessex by king Cenwalh. While Wulfhere did not directly control East Anglia he controlled Lindsey and Essex. By controlling all the surrounding lands, he probably forced East Anglia into a treaty. Wulfhere then made Athelwalh recognize his overlordship in Sussex. He expelled the West Saxons from Sussex and eastern Hampshire. Expanding to the east he made his Frithuwold King of Surrey in 670. When King Ecgberht of Kent died in 673 Wulfhere became the guardian of his two sons Eadric and Wihtred. He then ruled Kent through them. With Wulfhere's support, Theodore, the Archbishop of Canterbury presided over the Synod of Hertford in 673. In 674 Wulfhere decided to attack Northumbria. Oswiu's son Ecgfrith of Northumbria had put down a rebellion by the Picts when he became king. Wulfhere formed an alliance of most of the southern kings with the exception of Wessex. The southern alliance under Wulfhere was defeated by Ecgfrith in battle. While Wulfhere survived he was forced to pay to Ecgfrith. He soon lost his authority in Kent. Possibly in revenge for not joining him in fighting Northumbria, Wulfhere attacked Wessex. He was defeated by King Aescwine of Wessex in 674. Wulfhere died in early 675. He was succeeded as king by his brother Aethelred.