He was born sometime before 1347 to Count Conrad I of Oldenburg and Ingeborg of Brunswick.

After his father died in 1347, he ruled Oldenburg jointly with his elder brother Conrad II.

In 1403, his son Christian VI became joint ruler with his other son Dietrich, Count of Oldenburg, and with the son of Conrad II, Maurice II, who had previously ruled by himself from his father's death in 1401.

He married Agnes of Honstein, and the Danish Royal houses of Oldenburg and Schleswig-Holstein-Sonderburg-Glücksburg descend from him via his son and successor Dietrich, Count of Oldenburg.

Through the dynastic marriages of his descendants, he is an ancestor of many European Royal houses.