Polish–Lithuanian union in the context of "Composite monarchy"

Crimea (/kraɪˈmiːə/ kry-MEE-ə) is a peninsula in Eastern Europe, on the northern coast of the Black Sea, almost entirely surrounded by the Black Sea and the smaller Sea of Azov. The Isthmus of Perekop connects the peninsula to Kherson Oblast in mainland Ukraine. To the east, the Crimean Bridge, constructed in 2018, spans the Strait of Kerch, linking the peninsula with Krasnodar Krai in Russia. The Arabat Spit, located to the northeast, is a narrow strip of land that separates the Syvash lagoons from the Sea of Azov. Across the Black Sea to the west lies Romania and to the south is Turkey. The population is 2.4 million, and the largest city is Sevastopol. The region, internationally recognised as part of Ukraine, has been under Russian occupation since 2014.

Called the Tauric Peninsula until the early modern period, Crimea has historically been at the boundary between the classical world and the steppe. Greeks colonised its southern fringe and were absorbed by the Roman and Byzantine Empires and successor states while remaining culturally Greek. Some cities became trading colonies of Genoa, until conquered by the Ottoman Empire. Throughout this time the interior was occupied by a changing cast of steppe nomads, coming under the control of the Golden Horde in the 13th century from which the Crimean Khanate emerged as a successor state. In the 15th century, the Khanate became a dependency of the Ottoman Empire. Lands controlled by Russia and Poland-Lithuania were often the target of slave raids during this period. In 1783, after the Russo-Turkish War (1768–1774), the Russian Empire annexed Crimea. Crimea's strategic position led to the 1854 Crimean War and many short lived regimes following the 1917 Russian Revolution. When the Bolsheviks secured Crimea, it became an autonomous soviet republic within the Russian Soviet Federative Socialist Republic. It was occupied by Germany during World War II. When the Soviets retook it in 1944, Crimean Tatars were ethnically cleansed and deported under the orders of Joseph Stalin, in what has been described as a cultural genocide. Crimea was downgraded to an oblast in 1945. In 1954, the USSR transferred the oblast to the Ukrainian Soviet Socialist Republic on the 300th anniversary of the Pereyaslav Treaty in 1654.

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.

Between 1441 and 1774, the Crimean Khanate and the Nogai Horde conducted slave raids throughout lands primarily controlled by Russia and Poland–Lithuania. Concentrated in Eastern Europe, but also stretching to the Caucasus and parts of Central Europe, these raids were often supported by the Ottoman Empire and involved the transportation of European men, women, and children to the Muslim world, where they were put on the market and sold as part of the Crimean slave trade and the Ottoman slave trade. The regular abductions of people over the course of numerous incursions by the Crimeans and the Nogais greatly drained Eastern Europe's human and economic resources, consequently playing an important role in the emergence of the semi-militarized Cossacks, who organized retaliatory campaigns against the raiders and their Ottoman backers.

Trading posts in Crimea had previously been established by the Genoese and the Venetians to facilitate earlier Western European slave routes. The Crimean–Nogai raids largely targeted the "Wild Fields" of the Pontic–Caspian steppe, which extends about 800 kilometres (500 mi) north of the Black Sea and which now contains the majority of the combined population of southeastern Ukraine and southwestern Russia.

Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, and borders Lithuania and Russia to the northeast; Belarus and Ukraine to the east; Slovakia and the Czech Republic to the south; and Germany to the west. The territory has a varied landscape, diverse ecosystems, and a temperate climate. Poland is composed of sixteen voivodeships and is the fifth most populous member state of the European Union (EU), with over 38 million people, and the fifth largest EU country by land area, covering 312,696 km (120,733 sq mi). The capital and largest city is Warsaw; other major cities include Kraków, Wrocław, Łódź, Poznań, and Gdańsk.

Prehistoric human activity on Polish soil dates to the Lower Paleolithic, with continuous settlement since the end of the Last Glacial Period. Culturally diverse throughout late antiquity, in the early medieval period the region became inhabited by the West Slavic tribal Polans, who gave Poland its name. The process of establishing statehood coincided with the conversion of a pagan ruler of the Polans to Christianity in 966. Under the auspices of the Roman Catholic Church, the dominion became part of the Western world. In 1025, the Kingdom of Poland emerged, and in 1569 it cemented its long-standing association with Lithuania, forming the Polish–Lithuanian Commonwealth. At the time, the Commonwealth was one of Europe's great powers, with an elective monarchy and a uniquely liberal political system. It adopted Europe's first modern constitution in 1791.

Jogaila (Lithuanian: [jɔˈɡâːɪɫɐ] ; c. 1352/1362 – 1 June 1434), later Władysław II Jagiełło (Polish: [vwaˈdɨswaf jaˈɡʲɛwwɔ] ), was Grand Duke of Lithuania beginning in 1377 and starting in 1386, becoming King of Poland as well. As Grand Duke, he ruled Lithuania from 1377 to 1381 and from 1382 to 1401, at which time he became the Supreme Duke of Lithuania in exchange for naming his cousin Vytautas as the new Grand Duke. Władysław II initially served as King of Poland alongside his wife Jadwiga until her death in 1399, and then the sole ruler until his own death in 1434.

Raised a Lithuanian polytheist, he converted to Catholicism in 1386 and baptized as Ladislaus (Polish: Władysław) in Kraków, married the young Queen Jadwiga, and was crowned King of Poland as Władysław II Jagiełło. In 1387, he converted Lithuania to Catholicism. His reign in Poland started in 1399, upon the death of Queen Jadwiga, lasted a further thirty-five years, and laid the foundation for the centuries-long Polish–Lithuanian union. He was a member of the Jagiellonian dynasty in Poland that bears his name and was previously also known as the Gediminid dynasty in the Grand Duchy of Lithuania. The dynasty ruled both states until 1572, and became one of the most influential dynasties in late medieval and early modern Europe.

The Jagiellonian (US: /ˌjɑːɡjəˈloʊniən/ YAH-gyə-LOH-nee-ən) or Jagellonian dynasty (US: /ˌjɑːɡəˈ-/ YAH-gə-; Lithuanian: Jogailaičių dinastija; Polish: dynastia jagiellońska), otherwise the Jagiellon dynasty (Polish: dynastia Jagiellonów), the House of Jagiellon (Polish: Dom Jagiellonów), or simply the Jagiellons (Lithuanian: Jogailaičiai; Polish: Jagiellonowie; Latin: Iagellonidae), was the name assumed by a cadet branch of the Lithuanian ducal dynasty of Gediminids upon reception by Jogaila, the Grand Duke of Lithuania, of baptism as Ladislaus in 1386, which paved the way to his ensuing marriage to the Queen Regnant Hedwig of Poland, resulting in his ascension to the Crown of the Kingdom of Poland as Ladislaus II Jagiełło (initially ruling jure uxoris jointly with Jadwiga until her death), and the effective promotion of his branch to a royal dynasty. The Jagiellons were polyglots and per historical evidence Casimir IV Jagiellon and his son Saint Casimir possibly were the last Jagiellons who spoke in their patrilineal ancestors' Lithuanian language; however, even the last patrilineal Jagiellonian monarch Sigismund II Augustus maintained two separate and equally lavish Lithuanian-speaking and Polish-speaking royal courts in Lithuania's capital Vilnius. The Jagiellons reigned in several European countries between the 14th and 16th centuries. Members of the dynasty were Kings of Poland (1386–1572), Grand Dukes of Lithuania (1377–1392 and 1440–1572), Kings of Hungary (1440–1444 and 1490–1526), and Kings of Bohemia and imperial electors (1471–1526).

The personal union between the Kingdom of Poland and the Grand Duchy of Lithuania (converted in 1569 with the Treaty of Lublin into the Polish–Lithuanian Commonwealth) is the reason for the common appellation "Poland–Lithuania" in discussions about the area from the Late Middle Ages onward. One Jagiellon, Ladislaus III of Poland, briefly ruled both Poland and Hungary (1440–1444), and two others ruled both Bohemia and Hungary (1490–1526) and then continued in the distaff line as a branch of the House of Habsburg.