King of Mercia (626-655)
Very probably the first truly independent king of Mercia; according to the Historia Brittonum it was Penda who first separated the kingdom of Mercia from that of Northumbria.
The Anglo-Saxon Chronicle reports of the year 626 that,
This year Penda began to reign; and reigned thirty winters. He had seen fifty winters when he began to reign.
He followed an agressive expansionist policy and spent most of his reign at war with his fellow Anglo-Saxons
, busily extending the reach of the kingdom of Mercia
In 628 he fought against the West Saxon kings Cynegils and Cwichelm at
Cirencester; the Anglo-Saxon Chroncile says that they entered into a treaty afterwards, by which Penda seems to have acquired the territory of the Hwicce.
In 632 he formed an alliance with Cadwallon ap Cadfan ruler of Gwynedd; together they invaded Northumbria and slew its king Edwin at the battle of Meigen or Hatfield Moor. When Oswald subsequently re-established the kingdom of Northumbria, Penda continued the struggle. Again with the aid of Welsh allies he defeated and killed Oswald at the battle of Maserfield or Mirfield at Oswestry in 642.
In 645 he drove Kenwal, king of the West Saxons from his kingdom and was busily raiding Northumbria again in 651. By the 650's he was certainly the most powerful ruler in southern England, but this didn't last long. In 655 he undertook one invasion of Northumbria too many, when he was killed at the battle of the river Winwaed fighting Oswiu. Despite this he laid the foundations for the later dominant role of Mercia within Anglo-Saxon England.
Penda was famously a pagan and thus has attracted ever since the opprobrium of monastic chroniclers and commentators. The ninth-century Historia Brittonum, claimed that Penda was "victorious through the arts of the Devil" which was a convenient way of explaining his success in battle against so many avowedly Christian kings.
The twelfth-century chronicler Henry of Huntingdon in his Historia Anglorum, recorded the details of a short poem supposedly composed to celebrate the Penda's death at the battle of the river Winwaed in 655 that lists his victims;
At the Winweg was avenged the slaughter of Anna,
The slaughter of the kings Sigbert and Egric,
The slaughter of the kings Oswald and Edwin.
Despite remaining a pagan throughout his life, Penda appears to have been relatively unconcerned about matters of religion and permitted Christian missionaries to operate within Mercia and did nothing to prevent all his numerous progeny from adopting the Christian faith.