Louis IV of Germany, also known as Louis the Bavarian, was a king who ruled from 1314 to 1347. He was a member of the House of Wittelsbach and became the Holy Roman Emperor in 1328. His reign was marked by conflicts with the Pope and rival claimants to the throne, which led to a significant power struggle within the empire. Louis IV is known for his efforts to strengthen the authority of the monarchy and to centralize power in Germany. He also played a role in the Hundred Years' War by supporting the French against the English. His reign contributed to the political landscape of medieval Europe.