He and his elder brother John, husband of Sigismund's sister Margaret of Bohemia, fought in the 1396 Battle of Nicopolis where they suffered a disastrous defeat.

Sigismund claimed these rights for himself and designated Frederick to represent him as elector of Brandenburg in the imperial election of 20 September 1410.

Jobst's death under suspicious circumstances in January 1411 cleared the way for Sigismund's recovery of Brandenburg and his undisputed election as king of the empire later that year.

In gratitude for Frederick's services, King Sigismund made him Oberster Hauptmann and Verwalter der Marken (1411).

With an iron hand Frederick fought against the rebellious nobility of the March of Brandenburg (in particular, the Quitzow family) and, in the end, restored security.

He is best known for joining the papal legate Julian Cesarini in August 1431 to attack the Hussites in the disastrous Battle of Domažlice.