The Grand Duchy of Lithuania is a European state from the thirteenth century until 1795.

The state is founded by the Lithuanians, one of the polytheistic Baltic tribes from Aukštaitija.

The Grand Duchy later expands to include large portions of the former Kievan Rus' and other Slavic lands, covering the territory of present-day Belarus, Latvia, and Lithuania, and parts of Estonia, Poland, Russia, and Ukraine.

At its greatest extent in the fifteenth century, it is the largest state in Europe.

It is a multiethnic and multi-confessional state with great diversity in languages, religion, and cultural heritage.Consolidation of the Lithuanian lands begins in the late twelfth century.

Mindaugas, the first ruler of the Grand Duchy, is crowned as Catholic King of Lithuania in 1253.

The pagan state is targeted in the religious crusade by the Teutonic Knights and the Livonian Order.

The multiethnic and multi-confessional state emerges only at the late reign of Gediminas and continues to expand under his son Algirdas.Algirdas's successor Jogaila signs the Union of Krewo in 1386, bringing two major changes in the history of the Grand Duchy of Lithuania: conversion to Catholicism and establishment of a dynastic union between the Grand Duchy of Lithuania and the Crown of the Kingdom of Poland.