Frederick I,1371–1440, elector of Brandenburg (1415–40), first of the Hohenzollerns (see Hohenzollern, family) to rule Brandenburg. As Frederick VI, burgrave of Nuremburg, he served under King Sigismund of Hungary (later Holy Roman Emperor Sigismund) against the Ottomans in E Europe and took part in the battle of Nikopol (1396), in which the crusaders were defeated. As a reward for aiding Sigismund's election as emperor (1410), Sigismund granted (1411) Frederick a regency over Brandenburg and named him (1415) elector of Brandenburg; in 1417 he was formally invested with the electoral dignity. After subduing the recalcitrant nobles of Brandenburg, Frederick departed (1425) to command the imperial forces against the Hussites, but he later broke with Sigismund. His own ambition to be emperor was never fulfilled, but at his death the Hohenzollerns were well ensconced in Brandenburg.
