context: The history of Berlin starts with its foundation in the 13th century. It became the capital of the Margraviate of Brandenburg in 1417, and later of Brandenburg-Prussia, and the Kingdom of Prussia. Prussia grew rapidly in the 18th and 19th century, and formed the basis of the German Empire in 1871. After 1900 Berlin became a major world city, known for its leadership roles in science, the humanities, music, museums, higher education, government, diplomacy and military affairs.  It also had a role in manufacturing and finance. During World War II, it was virtually destroyed by bombing, artillery, and ferocious street-by-street fighting. It was split between the victors, and lost its world leadership roles.  With the reunification of Germany in 1990, Berlin was restored as a capital and as a major world city.
question: When was Berlin founded?
answers.text: 13th century 13th century 13th century