Abel, King of Denmark

Abel Valdemarsen (c. 1218 – 29 June 1252) was Duke of Schleswig from 1232 to 1252 and King of Denmark from 1250 until his death in 1252. He was the son of Valdemar II and his second wife, Berengaria of Portugal, and brother of kings Eric IV and Christopher I.

As Duke of Schleswig, Abel came into conflict with his brother, King Eric IV, whose murder in 1250 was suspected of orchestrating. Upon taking an oath to clear himself of the allegations, he was elected king. After a short reign, he was killed during a military expedition in Frisia.

Abel's reign was the shortest of any Danish monarch since the 9th century. He founded a line of dukes of Schleswig - the "Abel family" - which ruled the Duchy of Schleswig until 1375.

Source: Wikipedia — https://en.wikipedia.org/wiki/Abel,_King_of_Denmark