The Battle of Jankau, took place on 6 March 1645 during the later stages of the Thirty Years' War, near Jankov in Bohemia (today the Czech Republic). It featured 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 of their victory.
Imperial forces regained control of Bohemia in 1646, but inconclusive campaigns in the Rhineland and Saxony made it clear neither side had the strength to impose a military solution.