Germany: Icon of Louis IV (1282-1347), 25th Holy Roman emperor, from the book <i>Icones imperatorvm...

Louis IV (1282-1347), also known as Louis the Bavarian, was the son of Duke Louis II of Upper Bavaria and Matilda, daughter of King Rudolf I. He was of House Wittelsbach, and was initially a close friend to his Habsburg cousin Frederick the Fair, but they later fell out and violently clashed. He became Duke of Bavaria in 1301 alongside his brother Rudolf I, but became sole ruler in 1317.

When Emperor Henry VII died in 1313, two kings were elected to succeed him, one being Louis himself and the other his cousin Frederick. They were quickly crowned and then fought each other in a bloody war for several years, with Frederick poised to win until a decisive defeat in 1322 saw him captured by Louis. Louis later freed him in 1325, after Frederick recognised him as the legitimate King of Germany, and when Frederick returned to Louis as a prisoner when he could have easily fled after promising to try and covince his brothers to submit, Louis was so impressed by Frederick that he named him co-ruler of the Holy Roman Empire.

To Frederick went the title of King of Germany, while Louis was crowned as King of Italy in 1327 and Holy Roman Emperor in 1328. Louis found himself in conflict with the papacy and the pope, and in 1346 Charles IV of Luxembourg was elected as anti-king, supported by Pope Clement VI as a papal puppet. He successfully resisted Charles' attempts at usurpation, but Louis' sudden death in 1347 from a stroke while bear-hunting prevented a longer civil war from occurring and gave Charles the crown.