The history of Lithuania dates back to at least 1009, the first recorded written use of the term. Lithuanians later conquered neighboring lands, finally establishing the Kingdom of Lithuania in the 13th century. The Grand Duchy of Lithuania remained fiercely independent and was notably one of the last areas of Europe to adopt Christianity. In the 15th century, Lithuania became the largest state in Europe, merging into the Polish–Lithuanian Commonwealth and becoming a formidable power. In the 18th century, however, Lithuania was erased from the political map with the Partitions of Poland. The Lithuanians would live mostly under the rule of the Russian Empire until the 20th century.