Frederick I, Duke of Brunswick-Osterode
Frederick I, Duke of Brunswick-Osterode was a son of Duke Ernest I and his wife, Adelaide of Everstein-Polle.
In 1361, he succeeded his father as Count of Osterode.
He married Adelaide, a daughter of Bernhard V, Prince of Anhalt-Bernburg, and was the father of Otto II, who succeeded him. He may have also married Elizabeth, heiress of Homburg.