Title: Abel, King of Denmark
Content:  Abel Valdemarsen (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 by his second wife, Berengaria of Portugal, and brother to kings Eric IV and Christopher I. As Duke of Schleswig, Abel came into conflict with his brother, King Eric IV, whose murder in 1250 he 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.
Title: Abel, King of Denmark
Content:  and glowing hounds hunted across the moors and forest of Schleswig. Abel's descendants — the "Abel Family" — ruled South Jutland until 1375, often in co-operation with their relatives in Holstein. They created a permanent problem for the Danish government. Their rule meant the eventual separation of Frisia, Holstein, and most of Schleswig from the rest of Denmark. His great-grandson succeeded briefly as Valdemar III before being deposed. However, Abel's descendants would return to the throne with his great-granddaughter Helvig of Schleswig, who married Valdemar IV. Even though the line of Helvig died out with Christopher III, his successor Christian I was a descendant of Abel's through his daughter Sophie. Except for Christopher I through Valdemar IV, all subsequent Danish monarchs have been Abel's cognatic descendant.
Title: Abel, Lord of Langeland
Content:  Abel was born in 1252 as the third and posthumous son of King Abel of Denmark, Duke of Schleswig, by his wife, Mechtild of Holstein. In the settlement with his brother Eric after the death of their elder brother Duke Valdemar III, Abel received the cities of Svendborg, Rudkøbing, and possibly also Faaborg on the island of Funen, and as a fief the island of Langeland. Abel died on Easter Day 1279 in Svendborg and was buried in Greyfriars’ Abbey. At his death, he left only a daughter Margaret, who entered the convent of Zarrentin in Mecklenburg and donated her father's properties to her relatives, the counts of Holstein. They later sold it to King Eric VI of Denmark.
Title: Abel (given name)
Content: Abel, King of Denmark (1218–1252) ; Abel, Lord of Langeland (1252–1279) 
Title: Abel, King of Denmark
Content:  After clearing himself of the allegations taking the oath, Abel was proclaimed King of Denmark at the Viborg Assembly (Danish: landsting) on 1 November 1250. Abel only ruled for a year and a half. King Abel received word that the peasants in Frisia, led by Sicko Sjaerdema of Friesland, refused to pay the tax levy. Abel raised an army to punish them. At 33, he was killed by a wheelwright named Henner on Husum Bridge near Eiderstedt on 29 June 1252. At the time, Abel's half-grown son Valdemar (1238–1257) was held for ransom by the Archbishop of Cologne. So, Abel's youngest brother Christopher I was crowned King on Christmas Day 1252 in Lund Cathedral. After Abel's death, Queen Matilda entered a convent but subsequently bypassed her vows there to marry Swedish statesman Birger Jarl in 1261. Birger was an enemy of Abel's, and not long before Abel's death, Birger had started up a military vendetta against him which was only called off when the Danish king died.
Title: Abel, Lord of Langeland
Content:  Abel Abelsøn (1252 &ndash; 2 April 1279), Lord of Langeland, was the third son of King Abel of Denmark, Duke of Schleswig, and younger brother of Valdemar III, Duke of Schleswig and Eric I, Duke of Schleswig. As a member of the ducal family, he held several fiefs in Southern Denmark.
Title: Abel, King of Denmark
Content:  In 1232, at the election of his elder brother Eric as their father, King Valdemar II's co-ruler and heir, Abel was chosen to succeed Eric in his position as Duke of Schleswig. In 1237 he married Matilda of Holstein, a daughter of Adolf IV of Holstein (1205-1261). As Count Adolf withdrew to a Franciscan friary the same year, Abel spent several years acting as regent for his under age brothers-in-law, John I of Holstein-Kiel (1229–1263) and Gerhard I, Count of Holstein-Itzehoe (1232–1290).
Title: Søren Georg Abel
Content:  Søren Georg Abel (3 January 1772 – 5 May 1820) was a Norwegian priest and politician, also known as the father of mathematician Niels Henrik Abel.
Title: Niels Henrik Abel
Content:  Niels Henrik Abel was born in Nedstrand, Norway, as the second child of the pastor Søren Georg Abel and Anne Marie Simonsen. When Niels Henrik Abel was born, the family was living at a rectory on Finnøy. Much suggests that Niels Henrik was born in the neighboring parish, as his parents were guests of the bailiff in Nedstrand in July / August of his year of birth. Niels Henrik Abel's father, Søren Georg Abel, had a degree in theology and philosophy and served as pastor at Finnøy. Søren's father, Niels's grandfather, Hans Mathias Abel, was also a pastor, at Gjerstad Church near the town of Risør. Søren had spent his childhood at Gjerstad, and had also served as chaplain there; and after his 
Title: Abel, King of Denmark
Content: Valdemar III (1238–1257); Duke of Schleswig 1254–1257 ; Sophie (born 1240, d. aft. 1284), married Bernhard I, Prince of Anhalt-Bernburg. Their descendant was Christian I of Denmark. ; Eric I (c. 1241 – 27 May 1272); Duke of Schleswig 1260–1272 ; Abel (1252–1279) With his wife, Matilda of Holstein (ca. 1220 or 1225 – 1288) whom he married on 25 April 1237;

Question: Who is the father of Abel of Denmark?
Answer: Valdemar II of Denmark.