Christian IV, Count of Oldenburg

Christian IV (attested in charters 1302–1323) was Count of Oldenburg, eldest son of John II. In 1313 he promised to share rule with his infant half-brother Conrad I, and from 1316 he ruled jointly with his brother John III.

In 1317 the brothers styled themselves dukes of the Frisians, and in 1318 Christian alone called himself protector of the Frisians, pressing claims over Östringen and Rüstringen that never took effect. He left a daughter Jutta, and John III and Conrad I succeeded him.