Ludwig III was the last King of Bavaria, reigning from 1913 to 1918. Initially, he served in the Bavarian military as a lieutenant and went on to hold the rank of Oberleutnant during the Austro-Prussian War. He entered politics at the age of 18 becoming a member of the Bavarian parliament and was a keen participant in politics, supporting electoral reforms. Later in life, he served as regent and de facto head of state from 1912 to 1913, ruling for his cousin, Otto. After the Bavarian parliament passed a law allowing him to do so, Ludwig deposed Otto and assumed the throne for himself. He led Bavaria during World War I. His short reign was seen as championing conservative causes and he was influenced by the Catholic encyclical Rerum novarum.

The King of Bavaria was a title held by the hereditary Wittelsbach rulers of Bavaria in the state known as the Kingdom of Bavaria from 1805 until 1918, when the kingdom was abolished. It was the second time Bavaria was a kingdom, almost a thousand years after the short-lived Carolingian kingdom of Bavaria.