Union of Grodno (1432)

thumb|right|Poland and Lithuania 1386–1434

The Union of Grodno was a series of acts of the Polish–Lithuanian union between Kingdom of Poland and Grand Duchy of Lithuania. The first acts were signed in 1432 during the Lithuanian Civil War of 1432–1438. The acts confirmed the Union of Vilnius and Radom (1401). The Union established Sigismund Kęstutaitis as the Grand Duke of Lithuania and re-established Władysław II Jagiełło's seniority and dynastic interest in Lithuania.

Background

After death of Vytautas in 1430, the Lithuanian nobles unilaterally selected Švitrigaila as the new Grand Duke. This violated the terms of the Union of Horodło of 1413, where Lithuanians promised not to elect a new Grand Duke without an approval from Poland.