Fergus of Galloway married to David's older sister, Edith (died 1118), a union which closely bound him to the Scottish royal house. For as long as Henry I lived, relations between him and David remained harmonious. When the former died in 1135, however, the peace between the neighbouring realms was shattered when his nephew, Stephen of Blois, Count of Boulogne and Mortain (died 1154), successfully seized the throne. Before the end of the year, the Scots surged forth and seized Carlisle and Cumberland before peace was restored. Relations broke down the following year, and the Scots again invaded in 1137, seizing Northumberland, and
David, Prince of the Cumbrians the greatest warriors of the age, and applauded if they ended in conquest – nor should it be any surprise that he soon sought to express them upon Henry’s death. That he should seek to place those ambitions upon a solid basis of propriety would have been even less remarkable, had a suitable excuse to attack not been conveniently at hand. When Henry I died in 1135, David had already sat upon the throne of Scotland for nearly eleven years. He had also, in his capacity as a great English nobleman, been the first to swear obedience to Henry’s daughter,