The Battle of Jankau was one of the last major battles of the 1618 to 1648 Thirty Years' War, it was fought between Swedish and Imperial armies, each containing around 16,000 men. The more mobile and better led Swedes under Lennart Torstensson effectively destroyed their opponents, commanded by Melchior von Hatzfeldt. However, the devastation caused by decades of conflict meant armies now spent much of their time obtaining supplies, and the Swedes were unable to take advantage. Imperial forces regained control of Bohemia in 1646, but inconclusive campaigns in the Rhineland and Saxony made it clear neither side had the strength or resources to impose a military solution. Although fighting continued as participants tried to improve their positions, it increased the urgency of negotiations which culminated in the 1648 Peace of Westphalia.