In the 16th century, Mikael Agricola published the first written works in Finnish, and Finland's current capital city, Helsinki, was founded by Gustav I of Sweden. The first university in Finland, the Royal Academy of Turku, was established in 1640. The Finns reaped a reputation in the Thirty Years' War (1618–1648) as a well-trained cavalrymen called "Hakkapeliitta", that division excelled in sudden and savage attacks, raiding and reconnaissance, which King Gustavus Adolphus took advantage of in his significant battles, like in the Battle of Breitenfeld (1631) and the Battle of Rain (1632). Finland suffered a severe famine in 1696–1697, during which about one third of the Finnish population died, and a devastating plague a few years later.