Louis I (the Great), Ludwik Węgierski (1326 - 1382) became king of Hungary in 1342. He was the son of Charles I, king of Hungary, and was related to both the Angevin and Capetian royal families. Became a king of Poland in 1370.

Louis' mother was Elizabeth, the daughter of Ladislaus the Short, the sister of Casimir III the Great, king of Poland.

When the Polish Piast rulers died out in 1370, Louis became king of Poland.

Louis had three daughters:

• Catherine (deceased at a young age)
• Mary, Queen of Hungary, wife of Sigismund, Holy Roman Emperor, then Margrave of Brandenburg
• Hedwig (Queen Jadwiga of Poland).

Names in other languages: Hungarian: I (Nagy) Lajos, Polish: Ludwik Węgierski, Slovak: Ľudovít I (Veľký)