Louis IV, Holy Roman Emperor

Louis started as Duke of Upper Bavaria in 1294, sharing rule with his brother. His election as King of the Romans in 1314 split Germany - his Habsburg cousin Frederick the Fair was elected king the same day by a different faction. The standoff broke at the Battle of Mühldorf in 1322, where Louis crushed Frederick's forces, though the two later reconciled. Pope John XXII excommunicated him; Louis answered by marching to Rome, crowning himself Holy Roman Emperor in 1328, and attempting to install an anti-pope. He accumulated titles across decades - Margrave of Brandenburg, Count Palatine of the Rhine, Duke of Lower Bavaria - and when his wife Margaret inherited Hainaut, Holland, Zeeland, and Friesland in 1345, his reach stretched to the North Sea. He died in 1347, the last Bavarian to hold the German crown for four centuries.