Nils Jönsson Oxenstierna, (1390s-1450s) Swedish statesman and co-regent of Sweden, under the Kalmar Union, from January to June of 1448, together with his brother Bengt Jönsson Oxenstierna. Member of the Privy Council of Sweden at least 1432. Military governor, or hövitsman, at Borgholm Castle in 1436, Stäket in 1438, and Nyköping Castle in 1442. Dubbed as knight by King Christopher of Bavaria following his coronation in 1441.