Excerpts from Books and Wikipedia
"In 1518 Charles I became Holy Roman Emperor Charles V. His realms stretched from the Philippines to Peru and much of central and western Europe, but the troubled succession had only just started." [Furtado: 1001 Days] "Charles V revitalized the medieval concept of universal monarchy and spent most of his life defending the integrity of the Holy Roman Empire from the Protestant Reformation, the expansion of the Ottoman Empire, and a series of wars with France. With no fixed capital city, he made 40 journeys, travelling from country to country; he spent a quarter of his reign on the road. . . . Crowned King in Germany, Charles sided with Pope Leo X and declared Martin Luther an outlaw at the Diet of Worms (1521). . . . However, Henry II of France offered new support to the Lutheran cause and strengthened a close alliance with the sultan Suleiman the Magnificent, the ruler of the Ottoman Empire since 1520. Ultimately, Charles V conceded the Peace of Augsburg and abandoned his multi-national project with a series of abdications in 1556 that divided his hereditary and imperial domains between the Spanish Habsburgs headed by his son Philip II of Spain and the Austrian Habsburgs headed by his brother Ferdinand, who had been archduke of Austria in Charles's name since 1521 and the designated successor as emperor since 1531." [Wikipedia]