In the course of 17th-18th centuries, Tartu changed owners more often than any other Estonian town. Since 1558 it belonged to Tsarist Russia, since 1582 to Poland, 1600-1603 to the King of Sweden, 1603-1625 again to Poland, since 1625 again to Sweden, since 1656 to the Russians, and since 1661 until the Great Northern War, according to Kärde Peace, once more to Sweden. Due to numerous battles and fires, the town wall with bastion towers is almost entirely in ruins today.