Friedrich von Zollern

Friedrich von Zollern (c. 1316–1407) was the son of Count Friedrich VIII of Zollern, called Ostertag, and began as a churchman: promised an Augsburg canonry in 1327, he studied at Bologna and became a canon in 1346. He later gave that up to join the Hospitallers under Grand Master Dieudonné de Gozon, probably serving at Rhodes.

Back in Germany from 1361, he ran commanderies including Rohrdorf, Bubikon and Villingen. In 1382 he co-signed the Heimbach agreement, which gave the order's Brandenburg bailiwick wide autonomy, and in 1392 he became Prior of Germany.

At nearly eighty he joined King Sigismund's crusade against the Ottomans, and after the crushing defeat at Nicopolis in 1396 he covered the survivors' retreat down the Danube to the Black Sea. He resigned in 1398 and died at Rhodes in 1407, probably past ninety.