Oswiu

Unlike Oswald, Oswiu struggled to exert authority over Deira, the other constituent kingdom of medieval Northumbria, for much of his reign.

He secured control of Deira, with his son Alhfrith serving as a sub-king,[2] and for three years, Oswiu's power extended over Mercia, earning him recognition as bretwalda over much of Great Britain.

In 664, Oswiu presided over the Synod of Whitby, where clerics debated over the two traditions, and helped resolve tension between the parties by decreeing that Northumbria would follow the Roman style.

He was the third child of Æthelfrith, then King of Bernicia; his siblings included older brothers Eanfrith and Oswald and sister Æbbe.

[10] Regardless, his heritage did nothing to endear him to the Deiran nobility; while they accepted Oswald as king apparently on account of his mother, they resisted Oswiu throughout his reign.

[13] On Æthelfrith's death, his sons and their supporters fled Northumbria, finding sanctuary among the Gaels and Picts of northern Britain and Ireland.

[16] As well as learning the Irish language and being thoroughly Christianised, Oswiu may have fought for his Gaelic hosts, perhaps receiving his arms—a significant event—from a King of Dál Riata, such as Eochaid Buide, son of that Áedán mac Gabráin whom his father had defeated at the Battle of Degsastan.

[17] The Irish annals name one Oisiric mac Albruit, rigdomna Saxan—ætheling Osric—among the dead, alongside Connad Cerr, King of Dál Riata, and others of the Cenél nGabráin, at the Battle of Fid Eóin.

Unlike Eanfrith and Osric, Oswiu held to the Christian faith in spite of his brother's defeat by the pagan Penda.

[23]Oswiu's first recorded action as king of Bernicia was to strengthen his position, and perhaps his claims to Deira, by marrying Edwin's daughter Eanflæd, then in exile in the Kingdom of Kent.

[28] The first half of Oswiu's reign was spent in the shadow of Penda, who dominated much of Britain from 642 until 655, seemingly making and breaking kings as it suited him.

For the first decade of Oswiu's reign, Deira was ruled by an independent king, Oswine, son of the apostate Osric, who belonged to the rival Deiran royal family.

He himself, with only one trusty soldier, whose name was Tonhere, withdrew and lay concealed in the house of Earl [comes] Hunwald, whom he imagined to be his most assured friend.

Bede appears to place a major assault on Bernicia by Penda, which reached the gates of Bamburgh, at some time before 651 and the death of Bishop Aidan of Lindisfarne.

Bede states that Oswiu offered "an incalculable quantity of regalia and presents as the price of peace", but that Penda refused.

Oswiu vowed to give his daughter Ælfflæd to the church, and to found a dozen monasteries if he was granted the victory, and assisted by Ealhfrith he engaged Penda with a small army in the Battle of the Winwæd, which took place in the region of Loidis, which is to say Leeds.

[36] The Historia suggests that many of Penda's allies were British kings, and notes that Cadafael ap Cynfeddw joined Œthelwald in avoiding the battle, so gaining the epithet Cadomedd (the Battle-Shirker).

Further south, Æthelhere's brother Æthelwold may have been established with Oswiu's assistance, as well as that of his kinsman by marriage King Eorcenberht of Kent.

[42] While Wulfhere extended Mercian influence and authority in southern Britain, he apparently continued to recognise Oswiu's primacy.

[45] In 664 at the synod of Whitby,[46] Oswiu accepted the usages of the Roman Church, which led to the departure of Bishop Colmán of Lindisfarne.

[47] Bede writes that the dispute was brought to a head by Oswiu's son Ealhfrith, who had adopted Roman usages at the urging of Wilfrid.

[48] Ealhfrith had been brought up with Irish-Northumbrian usages, and his rejection of these, along with the expulsion of the future saints Cuthbert of Lindisfarne and Eata of Hexham from Ripon, is considered to have had a strong political component.

This gift is documented by Bede in Ecclesiastical History of the English People as part of a returning delegation from Rome, which had been led by Wighard.