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
The Anarchy the spoils. William's son Henry I seized power after the death of his elder brother William Rufus and subsequently invaded and captured the Duchy of Normandy, controlled by his eldest brother Robert Curthose, defeating Robert's army at the Battle of Tinchebray. Henry intended for his lands to be inherited by his only legitimate son, seventeen-year-old William Adelin. In 1120, the political landscape changed dramatically when the "White Ship" sank en route from Barfleur in Normandy to England; around three hundred passengers died, including Adelin. With Adelin dead, the inheritance to the English throne was thrown into doubt. Rules of succession