Sweyn III of Denmark

Sven III Grathe (app. 1125 - 1157) was the king of Denmark between 1146 and 1157. He served as a co-regent with Canute V of Denmark from 1152 until 1154 and again 1157.

Sweyn was the illegitimate son of Erik II Emune and a mistress.At the abdication of Eric III in 1146 Sweyn was elected a king on Zealand but for the next years he had to fight against his rival Canute V who ruled in Jutland. Sweyn participated in the Wendish Crusade of 1147. An Imperial German intervention made Sweyn “first king” with Canute as a co-ruler but Sweyn's position was undermined by his alleged tyrant manners and pro-German behaviour. 1154 he was overthrown by a co-operation between Canute and Valdemar I of Denmark, the latter having until then been his supporter. After some years of exile Sweyn was 1157 by German military help able to force through a tripartition of the kingdom making himself the ruler of Scania.

At a banquet (the so-called "Bloodfeast" at Roskilde) 1157 Sweyn is said to have tried to put his two co-rulers out of the way. Canute was killed, Valdemar escaped to Jutland and on 23 October Sweyn was defeated at the Battle of Grathe Heath (hence his nickname) and was killed during his escape.