Union of Krewo in the context of "History of Lithuania"

The Polish–Lithuanian Commonwealth, also referred to as Poland–Lithuania or the First Polish Republic (Polish: I Rzeczpospolita), was a federative real union between the Kingdom of Poland and the Grand Duchy of Lithuania, existing from 1569 to 1795. This state was among the largest, most populated countries of 16th- to 18th-century Europe. At its peak in the early 17th century, the Commonwealth spanned approximately 1,000,000 km (390,000 sq mi) and supported a multi-ethnic population of around 12 million as of 1618. The official languages of the Commonwealth were Polish and Latin, with Catholicism as the state religion.

The Union of Lublin established the Commonwealth as a single entity on 1 July 1569. The two nations had previously been in a personal union since the Krewo Agreement of 1385 (Polish–Lithuanian union) and the subsequent marriage of Queen Jadwiga of Poland to Grand Duke Jogaila of Lithuania, who was crowned as Władysław II Jagiełło, jure uxoris King of Poland. Their descendant, Sigismund II Augustus, enforced the merger to strengthen frontiers of his dominion and maintain unity. As he remained childless, his death in 1572 marked the end of the Jagiellonian dynasty. It introduced an elective monarchy, whereupon members of domestic noble families or external dynasties were elected to the throne for life.

Lublin is the eighth-largest city in Poland and the second-largest city of historical Lesser Poland. It is the capital and the centre of Lublin Voivodeship with a population of 336,339 (December 2021). Lublin is the largest Polish city east of the Vistula River, located 153 km (95 mi) southeast of Warsaw.

One of the events that greatly contributed to the city's development was the Polish–Lithuanian Union of Krewo in 1385. Lublin thrived as a centre of trade and commerce due to its strategic location on the route between Vilnius and Kraków; the inhabitants had the privilege of free trade in the Grand Duchy of Lithuania. The Lublin Parliament session of 1569 led to the creation of a real union between the Crown of the Kingdom of Poland and the Grand Duchy of Lithuania, thus creating the Polish–Lithuanian Commonwealth. Lublin witnessed the early stages of the Reformation in the 16th century. A Calvinist congregation was founded and groups of radical Arians appeared in the city, making it an important global centre of Arianism.

The Pact of Vilnius and Radom (Polish: Unia wileńsko-radomska, Lithuanian: Vilniaus-Radomo sutartis) was a set of three acts passed in Vilnius, Grand Duchy of Lithuania, and confirmed by the Crown Council in Radom, Kingdom of Poland in 1401. The union amended the earlier act of the Union of Krewo (1385) and confirmed the Ostrów Agreement (1392). Vytautas, Grand Duke of Lithuania, became fully in charge of the Lithuanian affairs, while Władysław II Jagiełło, King of Poland, reserved the rights of an overlord. After the death of Vytautas, Lithuania was to be ruled by Władysław II Jagiełło or his legal heir. The union is generally seen as strengthening of the Polish–Lithuanian union.

The Union of Horodło or Pact of Horodło was a set of three acts signed in the town of Horodło on 2 October 1413. The first act was signed by Władysław II Jagiełło, King of Poland, and Vytautas, Grand Duke of Lithuania. The second and third acts were composed by the Polish nobility (szlachta) and Lithuanian boyars, respectively. The union amended the earlier Polish–Lithuanian unions of Krewo and Vilnius–Radom. Politically, Lithuania received more autonomy as, after the death of Vytautas, the Lithuanian nobles could choose another Grand Duke instead of passing the title to Władysław II Jagiełło or his heir. However, culturally, Lithuania and Poland grew closer. Lithuania adopted Polish institutions of castellans and voivodes. Catholic Lithuanian nobles and church officials were granted equal rights with the Polish nobles and clergy. Forty-seven selected Lithuanian nobles were adopted by Polish families and granted Polish coats of arms. Thus the union signified the beginnings of the Polonization of Lithuanian culture and the rise of the Lithuanian nobility. It was one of the major steps towards the modernization and Europeanization of Lithuania.