Wulfhere or Wulfar (died 675) was King of Mercia from 658 until 675 AD. He was the first Christian king of all of Mercia, though it is not known when or how he converted from Anglo-Saxon paganism. His accession marked the end of Oswiu of Northumbria's overlordship of southern England, and Wulfhere extended his influence over much of that region. His campaigns against the West Saxons led to Mercian control of much of the Thames valley. He conquered the Isle of Wight and the Meon valley and gave them to King Æthelwealh of the South Saxons. He also had influence in Surrey, Essex, and Kent. He married Eormenhild, the daughter of King Eorcenberht of Kent.Wulfhere's father, Penda, was killed in 655 at the Battle of Winwaed, fighting against Oswiu of Northumbria. Penda's son Peada became king under Oswiu's overlordship but was murdered a year later. Wulfhere came to the throne when Mercian nobles organized a revolt against Northumbrian rule in 658 and drove out Oswiu's governors.By 670, when Oswiu died, Wulfhere was the most powerful king in southern Britain. He was effectively the overlord of Britain south of the Humber from the early 660s, although not overlord of Northumbria as his father had been. In 674, he challenged Oswiu's son Ecgfrith of Northumbria, but was defeated. He died, probably of disease, in 675. Wulfhere was succeeded as King of Mercia by his brother, Æthelred. Stephen of Ripon's Life of Wilfrid describes Wulfhere as "a man of proud mind, and insatiable will".