Christianization of Lithuania in the context of "Vytautas the Great"

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.

Paganism is commonly used to refer to various religions that existed during Antiquity and the Middle Ages, such as the Greco-Roman religions of the Roman Empire, including the Roman imperial cult, the various mystery religions, religious philosophies such as Neoplatonism and Gnosticism, and more localized ethnic religions practiced both inside and outside the empire. During the Middle Ages, the term was also adapted to refer to religions practiced outside the former Roman Empire, such as Germanic paganism, Egyptian paganism and Baltic paganism.

From the point of view of the early Christians, these religions all qualified as ethnic (or gentile, ethnikos, gentilis, the term translating goyim, later rendered as paganus) in contrast with Second Temple Judaism. By the Early Middle Ages (800–1000), faiths referred to as pagan had mostly disappeared in the West through a mixture of peaceful conversion, natural religious change, persecution, and the military conquest of pagan peoples; the Christianization of Lithuania in the 15th century is typically considered to mark the end of this process.

Romuva is a neo-pagan religion derived from the traditional mythology of the Lithuanians, attempting to reconstruct the religious rituals of the Lithuanians before their Christianization in 1387. Practitioners of Romuva claim to continue Baltic pagan traditions which survived in folklore, customs and superstition. Romuva is a polytheistic pagan faith which asserts the sanctity of nature and ancestor worship. Practicing the Romuva faith is seen by many adherents as a form of cultural pride, along with celebrating traditional forms of art, retelling Baltic folklore, practicing traditional holidays, playing traditional Baltic music, singing traditional dainos (songs), as well as ecological activism and stewarding sacred places.

Romuva primarily exists in Lithuania but there are also congregations of adherents in Australia, Canada, Russia, the United States, and England. There are believers of Baltic pagan faiths in other nations, including Dievturība in Latvia. According to the 2001 census, there were approximately 1,200 people in Lithuania identifying with Romuva. That number jumped to around 5,100 in the 2011 census.

The history of Lithuania dates back to settlements founded about 10,000 years ago, but the first written record of the name for the country dates back to 1009 AD. Lithuanians, one of the Baltic peoples, later conquered neighboring lands and established the Grand Duchy of Lithuania in the 13th century (and also a short-lived Kingdom of Lithuania). The Grand Duchy was a successful and lasting warrior state. It remained fiercely independent and was one of the last areas of Europe to adopt Christianity (beginning in the 14th century). A formidable power, it became the largest state in Europe in the 15th century spread from the Baltic Sea to the Black Sea, through the conquest of large groups of East Slavs who resided in Ruthenia.

In 1385, the Grand Duchy formed a dynastic union with Poland through the Union of Krewo. Later, the Union of Lublin (1569) created the Polish–Lithuanian Commonwealth. During the Second Northern War, the Grand Duchy sought protection under the Swedish Empire through the Union of Kėdainiai in 1655. However, it soon returned to being a part of the Polish–Lithuanian state, which persisted until 1795 when the last of the Partitions of Poland erased both independent Lithuania and Poland from the political map. After the dissolution, Lithuanians lived under the rule of the Russian Empire until the 20th century, although there were several major rebellions, especially in 1830–1831 and 1863.

Lithuania proper refers to a region that existed within the Grand Duchy of Lithuania where the Lithuanian language was spoken. The primary meaning is identical to the Duchy of Lithuania, a land around which the Grand Duchy of Lithuania evolved. The territory can be traced by Catholic Christian parishes established in pagan Baltic lands of the Grand Duchy of Lithuania subsequent to the Christianization of Lithuania in 1387. Lithuania proper (Lithuania Propria) was always distinguished from the Ruthenian lands since the Lithuanians differed from the Ruthenians in their language and faith (Paganism in the beginning and Catholicism since 1387). The term in Latin was widely used during the Middle Ages and can be found in numerous historical maps until World War I.

Lithuania proper is sometimes also called Lithuania Major, particularly in contrast with Lithuania Minor.

The list of Lithuanian gods is based on scarce written sources and late folklore. Many of them were outright invented. Lithuania converted to Christianity in 1387, but elements of Lithuanian mythology survived into the 19th century. The earliest written sources, authored by foreigners and Christians, only briefly mention the Lithuanian gods. Beginning in the 16th century, the pagan religion received more attention from authors, but often their accounts were confused, contradictory, and heavily influenced by various religious agendas. Collection and recording of folklore began in the 19th century, by which time the pagan mythology had become fragmented and mixed with Christian traditions. The cults of old deities transformed into folklore (individual tales, myths, songs, etc.) without associated rituals. Because of such difficulties in obtaining data, there is no accepted list of Lithuanian gods. Different authors present wildly contradictory reconstructions of the Lithuanian pantheon.

The Lithuanian Civil War of 1381–1384 was the first struggle for power between the cousins Jogaila, Grand Duke of Lithuania and later King of Poland, and Vytautas the Great. It began after Jogaila signed the Treaty of Dovydiškės with the Teutonic Knights which was aimed against his uncle Kęstutis, father of Vytautas. Kęstutis briefly seized power in the Grand Duchy, but was betrayed by adherents of Jogaila primarily from Vilnius. During negotiations for a truce Kęstutis and Vytautas were arrested and transported to the Kreva Castle. Kęstutis died there a week later but Vytautas managed to escape and then sought an alliance with the Teutonic Knights. Subsequently their joint forces raided Lithuanian lands. Eventually the cousins were reconciled as Jogaila needed internal stability in anticipation of negotiations with the Grand Duchy of Moscow and the Kingdom of Poland regarding the possible Christianization of Lithuania. The war did not settle the power struggle; it continued during the next Lithuanian Civil War (1389–1392) which was resolved by the signing of the Ostrów Agreement. After more than ten years of struggle, Vytautas finally became the Grand Duke of Lithuania and ruled the country for thirty-eight years.