Magnates of Poland and Lithuania

The magnates of Poland and Lithuania (Polish: magnateria, Lithuanian: magnatai) were an aristocracy of Polish-Lithuanian nobility (szlachta) that existed in the Crown of the Kingdom of Poland, in the Grand Duchy of Lithuania and, from the 1569 Union of Lublin, in the Polish–Lithuanian Commonwealth, until the Third Partition of Poland in 1795. The magnate social class arose around the 16th century and, over time, gained more and more control over Commonwealth politics.

Source: Wikipedia — Magnates of Poland and Lithuania (CC BY-SA 4.0)