Mindaugas (; ca. 1200 – 12 September 1263) was the first known Grand Duke of Lithuania and the only King of Lithuania. Little is known of his origins, early life, or rise to power; he's 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 12… (More on Mindaugas)