The Hessian War, in its wider sense sometimes also called the Hessian Wars (Hessenkriege), was a drawn out conflict that took place between 1567 and 1648, sometimes pursued through diplomatic means, sometimes by military force, between branches of the princely House of Hesse, particularly between the Landgraviate of Hesse-Cassel and the Landgraviate of Hesse-Darmstadt. It was triggered by a division of inheritance following the death of the last landgrave of all Hesse, Philip I in 1567.

The Peace of Prague, dated 30 May 1635 Old Style, was a significant turning point in the Thirty Years' War. Signed by John George I, Elector of Saxony, and Ferdinand II, Holy Roman Emperor, the terms ended Saxony's support for the anti-Imperial coalition led by Sweden.