Oswald died in battle against Penda of Mercia at the
Battle of Maserfield, dated by Bede to 5 August 642. Oswald's son
Œthelwald may have been his preferred successor, but Œthelwald cannot have been an adult in 642. So, the kingship came to Oswiu. Unlike Eanfrith and Osric, Oswiu held to the Christian faith in spite of his brother's defeat by the pagan Penda. This may have been due to his more thoroughly Christian upbringing, but the influence of Bishop
Aidan of Lindisfarne, by then a major figure in Bernicia, could also have been significant. Bede summarises Oswiu's reign in this way:Oswald being translated to the heavenly kingdom, his brother Oswy, a young man of about thirty years of age, succeeded him on the throne of his earthly kingdom, and held it twenty-eight years with much trouble, being harassed by the pagan king, Penda, and by the pagan nation of the Mercians, that had slain his brother, as also by his son Alfred [i.e.
Ealhfrith], and by his
cousin-german Ethelwald [i.e. Œthelwald of Deira], the son of his brother who reigned before him. 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. This marriage took place between 642 and 644. Oswiu is known to have been married three times. Eanflæd, his Queen, bore him two sons and two daughters. The sons were
Ecgfrith (644/645–685) and
Ælfwine (c. 660–679), the daughters
Osthryth (died 697) and
Ælfflæd (c. 654–714). The Irish princess
Fín was the mother of
Aldfrith (died 705). Finally, the
British princess
Rieinmelth of
Rheged is named as a wife of Oswiu in the
Historia Brittonum. It is thought that Ealhfrith was her son, and Eahlflæd may have been her daughter. 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. The future kingdom of Northumbria was still composed of two distinct kingdoms in Oswiu's lifetime. The northerly kingdom of
Bernicia, which extended from the
River Tees to the
Firth of Forth, was ruled by Oswiu. The kingdom of
Deira, lying between the
North York Moors and the
Humber, was ruled by a series of Oswiu's kinsmen, initially as a separate kingdom, later as a form of
appanage for Oswiu's sons. 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. Oswine and Oswiu came into conflict circa 651. Bede blames Oswiu for the troubles and writes:For when they had raised armies against one another, Oswin perceived that he could not maintain a war against one who had more auxiliaries than himself, and he thought it better at that time to lay aside all thoughts of engaging, and to preserve himself for better times. He therefore dismissed the army which he had assembled, and ordered all his men to return to their own homes, from the place that is called Wilfaresdun, that is, Wilfar's Hill, which is almost ten miles distant from the village called Cataract [i.e.
Catterick], towards the north-west. 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. But, alas! it was otherwise; for the earl betrayed him, and Oswy, in a detestable manner, by the hands of his commander [
praefectus], Ethilwin, slew him... In order to expiate the killing of Oswine, who was later reckoned a
saint, Oswiu established
Gilling Abbey at
Gilling, where prayers were said for Oswine and for Oswiu. Oswine was followed as king of the Deirans by Oswald's son Œthelwald. ==Penda==