Siward or Sigurd (Old English: Sigeweard) was an important earl of 11th-century northern England. The Old Norse nickname Digri and its Latin translation Grossus ("the stout") are given to him by near-contemporary texts. Siward was probably of Scandinavian origin, perhaps a relative of Earl Ulf, and emerged as a powerful regional strongman in England during the reign of Cnut ("Canute the Great", 1016–1035). Cnut was a Scandinavian ruler who conquered England in the 1010s, and Siward was one of the many Scandinavians who came to England in the aftermath of that conquest. Siward subsequently rose to become sub-ruler of most of northern England. From 1033 at the latest Siward was in control of southern Northumbria, that is, present-day Yorkshire, governing as earl on Cnut's behalf.