Vilnius Cathedral in the context of "Gediminas' Cap"

The article is a list of heads of state of Lithuania over historical Lithuanian state. The timeline includes all heads of state of Lithuania as a sovereign entity, legitimately part of a greater sovereign entity, a client state, or a constituent republic subject to an outside authority. Currently, the head of state is the President of Lithuania.

During the inaugurations of Lithuanian monarchs until 1569, the Gediminas' Cap was placed on the monarch's heads by the Bishop of Vilnius in Vilnius Cathedral.

The House of Gediminas (Lithuanian: Gediminaičių dinastija), or simply the Gediminids, were a dynasty of monarchs in the Grand Duchy of Lithuania that reigned from the 14th to the 16th century. A cadet branch of this family, known as the Jagiellonian dynasty, reigned also in the Kingdom of Poland, Kingdom of Hungary and Kingdom of Bohemia. Several other branches ranked among the leading aristocratic dynasties of Poland and Russia into recent times.

Gediminas' Cap was used during the inaugurations of Gediminids as Lithuanian monarchs in the Vilnius Cathedral and symbolized the dynasty's continuity.

Casimir Jagiellon (/ˈkæzɪmɪər/; Latin: Casimirus; Lithuanian: Kazimieras; Polish: Kazimierz; 3 October 1458 – 4 March 1484) was a prince of the Kingdom of Poland and of the Grand Duchy of Lithuania. The second son of King Casimir IV Jagiellon, he was tutored by Johannes Longinus, a Polish chronicler, diplomat, and priest. After his elder brother Vladislaus was elected as King of Bohemia in 1471, Casimir became the heir apparent. At the age of 13, Casimir participated in the failed military campaign to install him as King of Hungary. He became known for his piety, devotion to God, and generosity towards the sick and poor. He became ill (most likely with tuberculosis) and died at the age of 25. He was buried in Vilnius Cathedral. His canonization was initiated by his brother King Sigismund I the Old in 1514 and the tradition holds that he was canonized in 1521. Saint Casimir the Prince is the patron saint of Poland, Lithuania and Lithuanian youth and the only saint with this name.

Veneration of Casimir saw a resurgence in the 17th century when his feast day was confirmed by the pope in 1602 and the dedicated Chapel of Saint Casimir was completed in 1636. Casimir became a patron saint of Lithuania and Lithuanian youth. In Vilnius, his feast day is marked annually with Kaziuko mugė (a trade fair) held on the Sunday nearest to 4 March, the anniversary of his death. There are more than 50 churches named after Casimir in Lithuania and Poland, including Church of St. Casimir, Vilnius and St. Kazimierz Church, Warsaw, and more than 50 churches in Lithuanian and Polish diaspora communities in America. Women's congregation Sisters of Saint Casimir was established in 1908 and remains active in the United States.

The Catholic Church in Lithuania (Lithuanian: Katalikų Bažnyčia Lietuvoje) is part of the worldwide Catholic Church, under the spiritual leadership of the Pope in Rome. Lithuania is the world's northernmost Latin Catholic-majority country. Pope Pius XII gave Lithuania the title of "northernmost outpost of Catholicism in Europe" in 1939. The Vilnius Cathedral is the most important Catholic Church in Lithuania, which was previously used for the inauguration ceremonies of Lithuanian monarchs with Gediminas' Cap, while in modern times it is a venue for masses dedicated to the elected Presidents of Lithuania after their inauguration ceremonies and giving of oaths to the Nation in the Seimas Palace.

Among the Baltic states, Lithuania is the country with the highest percentage of Catholic population. Almost three-quarters (74.19%) of Lithuania's population self-identified as Catholics in the 2021 census. The country is divided into eight dioceses including two archdioceses and a military ordinariate.

The Chapel of Saint Casimir is a Roman Catholic chapel, that is dedicated to Saint Casimir, located in the Vilnius Cathedral, in Vilnius, Lithuania. The chapel was built in 1623–36 after Prince Casimir (1458–1484) was canonized as saint. It was built and decorated in the Baroque style by Italian sculptors and architects commissioned by Sigismund III Vasa, King of Poland and Grand Duke of Lithuania. The centerpiece of the chapel is a faux marble altar which holds the silver sarcophagus with Casimir's remains and the painting Three-Handed St. Casimir.