Dietrich, Count of Oldenburg

Dietrich of Oldenburg
Count of Oldenburg
Predecessor	Christian V of Oldenburg
Successor	Christian VII
Spouse(s)	Countess Adelheid of Oldenburg-Delmenhorst Helvig of Schauenburg
Issue Christian I of Denmark Maurice V of Delmenhorst Gerhard VI, Count of Oldenburg Adelheid, Countess of Hohenstein and Mansfeld
Noble family	House of Oldenburg
Father	Christian V, Count of Oldenburg
Mother	Countess Agnes of Honstein
Born	c. 1398
Died	14 February 1440 (aged 41–42)

Countess Adelheid of Oldenburg-Delmenhorst

Derrick or Dietrich of Oldenburg, Latin-based Anglicisation also Theoderic of Oldenburg (c. 1398 – 14 February 1440), nicknamed Theoderic the Lucky or the Fortunate (Teudericus Fortunatus), was a feudal lord in Northern Germany, holding the counties of Delmenhorst and Oldenburg. He was called "Fortunatus" as he was able to secure Delmenhorst for his branch of the Oldenburgs.

Dietrich was the father of Christian I of Denmark, a male-line ancestor to the present-day Danish throne under Margarethe II of Denmark as well as the last Czar of imperial Russia, Nicolas II. He is also the male line ancestor of Charles, Prince of Wales and Harald V of Norway.

Dietrich of Oldenburg was the son of Christian V of Oldenburg (who became count in about 1398 and died in 1423) and his wife, Countess Agnes of Honstein (c. 1410–1460). His grandfather, Conrad I of Oldenburg (d. ca. 1368) had left his lands divided between Dietrich's father and uncle, Conrad II.

Dietrich’s father, Christian V, managed to gain the upper hand when Conrad II's son Maurice II died in 1420. After this, most of the Oldenburg family patrimony was under the power of Dietrich’s branch. However, the house had several minor branches that had estates and claims, as was usual in any medieval fief.

Dietrich of Oldenburg was the grandson of Ingeborg of Itzehoe, a Holstein princess who had married count Conrad I of Oldenburg. After the death of her only brother in 1350, Count Gerhard V of Holstein-Itzehoe-Plön, Ingeborg and her issue were the heirs of her own grandmother Ingeborg of Sweden (d. ca. 1290, first wife of Gerhard II of Holstein-Plön), the eldest daughter of King Valdemar of Sweden and Queen Sophia, who herself was the eldest daughter of the sonless King Eric IV of Denmark and his wife Jutta of Saxony. Since other legitimate descent from King Valdemar apparently was extinct by this time, Dietrich was considered the heir general of Kings Valdemar I of Sweden and Eric IV of Denmark.