The Union of Lublin in 1569 was a landmark agreement between the Kingdom of Poland and the Grand Duchy of Lithuania that established the Polish–Lithuanian Commonwealth. It marked the end of the Polish–Lithuanian personal union, which had been in place since the
The Union of Lublin was signed on 1 July 1569 in Lublin, Poland, and created a single state, the Polish–Lithuanian Commonwealth, one of the largest countries in Europe at the time. It replaced the personal union of the Crown of the Kingdom of Poland and the Grand Duchy of Lithuania with a real union and an elective monarchy, as Sigismund II Augustus, the last of the Jagiellons, remained childless after three marriages. In addition, the autonomy of Royal Prussia was largely abandoned. The Duchy of Livonia, tied to Lithuania in real union since the Union of Grodno (1566), became a Polish–Lithuanian condominium.