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
Battle of the Standard and in the settling of regained territory, he had drawn on the talent and resources of the Anglo-Norman lands. The death of Henry I in 1135, weakening England, made David more reliant on his native subjects, and allowed him to contemplate winning control over substantial areas of northern England. Henry I had wished his inheritance to pass to his daughter Matilda, and in 1127 made his notables swear an oath to uphold the succession of Matilda (David was the first layman to do so). Many of the English and Norman magnates and barons were against Matilda because she was married