Polish-Lithuanian Commonwealth Anthem (until 1795) Gaude Mater Polonia

The Polish–Lithuanian Commonwealth (1569–1795), formally known as the Crown of the Kingdom of Poland and the Grand Duchy of Lithuania was a country and bi-federation of Poland and Lithuania ruled by a common monarch in real union, who was both King of Poland and Grand Duke of Lithuania. It was the largest and one of the most populous countries of 16th- and 17th-century Europe.
"Gaude Mater Polonia" (Medieval Latin for "Rejoice, oh Mother Poland"; Polish: "Raduj się, matko Polsko") was one of the most significant medieval Polish hymns. It's widely considered a historical, national anthem of the Kingdom of Poland and the Polish–Lithuanian Commonwealth.