He was born around 1460 as the son of Nils Bosson of the family of Natt och Dag (whose mother was of Sture family). He never himself used the name Sture, but his son later took the great-grandmother's name because of its prestige and tradition of preserving the Swedish independence. He became a member of the Privy Council of Sweden no later than 1482, but acted in opposition to his distant kinsman Sten Sture the Elder, going as far as supporting John of Denmark. Unwillingly he then switched sides and supported Sten Sture in overthrowing the king, which at the death of Sten Sture led to himself being elected regent. From 1501 he was at war with Denmark. His resignation was demanded by the Privy Council of Sweden in the summer of 1511, but in practice he remained in power until his death on 2 January 1512.