Otto was born in Mosbach in 1390 as the youngest son of Rupert III of the Palatinate, King of Germany. In 1410 after the death of his father, the territories of the Palatinate were divided between his four sons. Otto received the territory around Mosbach and Eberbach.
He made Mosbach his capital and began the construction of a new residence there. He held the regency until 1442. Otto died in Reichenbach am Regen in 1461 and was buried in the Benedictine Abbey of Reichenbach.
Otto married Joanna of Bavaria-Landshut (1413 - 20 July 1444), daughter of duke Henry XVI in January in 1430 and had the following children:.
