He belonged to the powerful Hvide clan, and was foster brother to King Valdemar I the Great. He was an educated scholar that had studied theology at the University of Paris 1146 to 1156.
He took side with his foster brother Valdemar during the political turmoil that made him solitary king of Denmark in 1157. Absalon was rewarded as the king made him Archbishop of Roskilde, and was given the area around today's Copenhagen as his personal property in 1160. He remained deeply loyal to the king as a confidant and councellor.
Here he built his fortress, that stood from 1167 to 1369, when it was destroyed by an army from the Hanseatic town of Lübeck. It was rebuilt in bricks. Excavations in 1907 found the remains of the old fortress under Christiansborg Castle.
Absalon died in 1201, and was buried in the Church at Sorø Monastery, that he had commissioned in 1161. His grave was opened in 1567, and then they found a golden ring with a sapphire on his right hand.
Absalons ring is now on display at the Museum of Roskilde Cathedral