Nils Jönsson (Oxenstierna)

Nils Jönsson Oxenstierna, (1390s–1450s) was a Swedish statesman and co-regent of Sweden, under the Kalmar Union, from January to June 1448, together with his brother Bengt Jönsson Oxenstierna. Member of the Privy Council of Sweden at least 1432. Castellan (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.

Nils Jönsson was son of important nobles and landowners: his mother lady Märta Finvidsdotter was the heiress of the Frössvik high-noble family, and his father Jöns Bengtsson was son and one of the heirs of lady Ingeborg Nilsdotter (from family that is called the earliest Sparre in later historiography and genealogy), heiress of Ängsö and Salsta. Jöns Bengtsson inherited Frössvik (in Uppland) from mother and Ängsö (in Västmanland) from father. Nils is credited for having founded the castle of Djursholm in his lands.

From his two earlier marriages, Nils did not succeed to have any surviving heirs. His third wife lady Karin of the gumsehuvud-sture family bore a number of children (of whom, as is usual in Middle Ages, half died sooner or later without marriage and issue). His surviving son Erik did not have children. Three of Nils' daughters married noblemen (two of them sons of the Vasa family, Nils' allies), but only through one of them, Kerstin who married lord Nils of Hjulsta, continues a more permanent issue. Due to such childlessness, a portion of Nils' properties passed ultimately to others than his own descendants, as inheritances through his daughters-in- and sons-in-law.