Ulf (or Ulf Jarl) (Ulf Thorgilsson) was a Danish earl (jarl) and regent of Denmark. Ulf was the father of King Sweyn II of Denmark and thus the progenitor of the House of Estridsen, which would rule Denmark from 1047 to 1375, which was also sometimes, specially in Swedish sources, referred to as the Ulfinger dynasty to honor him. [1]
https://en.m.wikipedia.org/wiki/Sweyn_II_of_Denmark | Sweyn II Estridsson[2] (Old Norse: Sveinn Ástríðarson, Danish: Svend Estridsen) (c. 1019 – 28 April 1076[3][4]) was King of Denmark from 1047 until his death in 1076. He was the son of Ulf Thorgilsson and Estrid Svendsdatter, and the grandson of King Sweyn I Forkbeard through his mother\'s line. He was married three times, and fathered 20 children or more out of wedlock, including the five future kings Harald III Hen, Canute IV the Saint, Oluf I Hunger, Eric I Evergood, and Niels.