1911 Encyclopædia Britannica/Siward
SIWARD (d. 1055), earl of Northumbria, was a Dane by birth and probably came to England with Canute. He became earl of Deira after the death of Eadwulf Cutel, earl of Northumbria, about 1038, and earl of all Northumbria after murdering Eadwulf, earl of Bernicia, in 1041. He supported Edward the Confessor in his quarrel with Earl Godwine in 1051, and was appointed earl of Huntingdon soon after this date. In 1054 Siward invaded Scotland in the interests of his kinsman Malcolm Canmore, and he completely routed King Macbeth in a battle in which his son Osbeorn was killed. Early in 1055 the earl died at York. Shakespeare introduces Siward and his son, whom he calls young Siward, into the tragedy of Macbeth, and represents the old man as saying when he heard that his son's wounds were in front, “Had I as many sons as I have hairs, I would not wish them to a fairer death.” Siward, a man of unusual strength and size, is said to have risen from his bed at the approach of death, and to have died dressed in all his armour. He built a minster near York which he dedicated to St Olaf, and where he was buried; and one of his sons was Earl Waltheof.
See E. A. Freeman, The Norman Conquest, vols. ii. and iii. (1870–1876); and W. F. Skene, Celtic Scotland (1876–1880).