History of the Polish–Lithuanian Commonwealth (1569–1648)
The history of the Polish–Lithuanian Commonwealth (1569–1648) covers a period in the history of Poland and Lithuania, before their joint state was subjected to devastating wars in the mid-17th century. The Union of Lublin of 1569 established the Polish–Lithuanian Commonwealth, a more closely unified federal state, replacing the previously existing personal union of the two countries.
Source: Wikipedia — History of the Polish–Lithuanian Commonwealth (1569–1648) (CC BY-SA 4.0)