The history of Lithuania dates back to settlements founded many thousands of 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 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 that lasted until 1795, when the last of the Partitions of Poland erased both Lithuania and Poland from the political map. After the dissolution, Lithuanians lived under the rule of the Russian Empire until the 20th century, although the were several major rebellions, especially in 1830–1831 and 1863.