The House of Normandy is the usual designation for the family that were the Dukes of Normandy and Kings of England which immediately followed the Norman conquest of England and lasted until the House of Plantagenet came to power in 1154. It included the Norwegian Viking Rollo and his descendants, and from William the Conqueror and his heirs down through 1135. After that it was disputed between William's grandchildren, Matilda and Stephen of the House of Blois (or Blesevin dynasty).