This document summarizes key figures and events in the rivalry between the Holy Roman Empire led by Charles V and the Ottoman Empire led by Suleiman the Magnificent in the 16th century. It describes Charles V becoming Holy Roman Emperor and fighting to maintain Catholic control of Europe against the Ottomans and heretics. It also outlines Suleiman's early victories expanding the Ottoman Empire and his appointment of Hayrettin Barbarossa as Grand Admiral, who led brutal attacks along the coast of the Roman Empire.