Editing Northumbria (section)

===Politics and war===
{{main|List of monarchs of Northumbria}}
Between 737&nbsp;and 806, Northumbria had ten kings,<ref>{{harvnb|Petts|Turner|2011|pp=14–27}}</ref> all of whom were murdered, deposed, or exiled or became monks. Between [[Oswiu]], the first king of Northumbria in 651, and [[Eric Bloodaxe]], the last king of Northumbria in 954, there were forty-five kings, meaning that the average length of reign during the entire history of Northumbria is only six and a half years. Of the twenty-five kings before the Danish rule of Northumbria, only four died of natural causes. Of those that did not abdicate for a holy life, the rest were either deposed, exiled, or murdered. Kings during the Danish rule of Northumbria (see [[Danelaw]]) were often either kings of a larger North Sea or Danish empire, or were installed rulers.<ref>{{harvnb|Downham|2007|pp=40}}</ref>

Succession in Northumbria was hereditary,<ref>{{harvnb|Petts|Turner|2011|p=27}}</ref> which left princes whose fathers died before they could come of age particularly susceptible to assassination and usurpation. A noteworthy example of this phenomenon is Osred, whose father Aldfrith died in 705, leaving the young boy to rule. He survived one assassination attempt early in his rule, but fell victim to another assassin at the age of nineteen. During his reign he was adopted by Wilfrid, a powerful bishop.<ref>{{Harvnb|Higham|1993|pp=81–90}}</ref> Ecclesiastical influence in the royal court was not an unusual phenomenon in Northumbria, and usually was most visible during the rule of a young or inexperienced king. Similarly, ealdorman, or royal advisors, had periods of increased or decreased power in Northumbria, depending on who was ruling at the time.<ref>{{harvnb|Fairless|1994|pp= 10–16}}</ref>

Warfare in Northumbria before the Danish period largely consisted of rivalries with the [[Picts]] to the north. The Northumbrians were successful against the Picts until the [[Battle of Dun Nechtain]] in 685, which halted their expansion north and established a border between the two kingdoms.<ref>{{cite thesis |last=Parsons|first=Julie|date=4 May 2002|title=The First Battle for Scottish Independence: The Battle of Dunnichen, A.D.&nbsp;685. |type=MA thesis |publisher=East Tennessee State University |url=https://dc.etsu.edu/etd/657}}</ref> Warfare during the Danish period was dominated by warfare between the Northumbrians and other English Kingdoms.