Mindaugas is crowned King of Lithuania.

Mindaugas was the first known Grand Duke of Lithuania and the only crowned King of Lithuania. Little is known of his origins, early life, or rise to power; he is mentioned in a 1219 treaty as an elder duke, and in 1236 as the leader of all the Lithuanians. The contemporary and modern sources discussing his ascent mention strategic marriages along with banishment or murder of his rivals. He extended his domain into regions southeast of Lithuania proper during the 1230s and 1240s. In 1250 or 1251, during the course of internal power struggles, he was baptised as a Roman Catholic; this action enabled him to establish an alliance with the Livonian Order, a long-standing antagonist of the Lithuanians. By 1245, Mindaugas was already being referred to as "the highest king" in certain documents. During the summer of 1253, he was crowned king, ruling between 300,000 and 400,000 subjects, and got nicknamed as Mindaugas the Sapient by the Livonians.

Lithuania, officially the Republic of Lithuania, is a country in the Baltic region of Europe. It is one of three Baltic states and lies on the eastern shore of the Baltic Sea, bordered by Latvia to the north, Belarus to the east and south, Poland to the south, and the Russian semi-exclave of Kaliningrad Oblast to the southwest, with a maritime border with Sweden to the west. Lithuania covers an area of 65,300 km² (25,200 sq mi), with a population of 2.9 million. Its capital and largest city is Vilnius; other major cities include Kaunas, Klaipėda, Šiauliai and Panevėžys. Lithuanians are the titular nation, belong to the ethnolinguistic group of Balts, and speak Lithuanian.