The emperor then succeeded in disrupting the Schmalkaldic League by winning over, on purely political grounds, Philip of Hesse and young Maurice of Saxony, whose father, Henry, had died after a very brief reign.
After being part of Thuringia, Eschwege passed to Hesse in 1263.
The harmonious relations which subsisted between the two branches of the Wettins were disturbed by the interference of Maurice in Cleves, a proceeding distasteful to the Saxon elector, John Frederick; and a dispute over the bishopric of Meissen having widened the breach, war was only averted by the mediation of Philip of Hesse and Luther.
The land, which fell into two main portions, upper Hesse round Marburg, and lower Hesse round Cassel, was twice divided between two members of the ruling family, but no permanent partition took place before the Reformation.
In 1803, having formally surrendered the part of Hesse on the left bank of the Rhine which had been taken from him in the early days of the Revolution, Louis received in return a much larger district which had formerly belonged to the duchy of Westphalia, the electorate of Mainz and the bishopric of Worms. In 1806, being a member of the confederation of the Rhine, he took the title of Louis I., grandduke of Hesse; he supported Napoleon with troops from 1805 to 1813, but after the battle of Leipzig he joined the allies.
The assertions of Otto von Pack that a league had been formed against the elector and his friends induced John to ally himself again with Philip of Hesse in March 1528, but he restrained Philip from making an immediate attack upon their opponents.
Fighting began along the upper Danube, and when indecision and want of funds had ruined the league's chances of success, Philip returned to Hesse and busied himself with seeking help from foreign powers; while in April 1547 John Frederick was captured at Miihlberg.
For nearly 300 years the history of Hesse is comparatively uneventful.
When he died in 1567 Hesse was divided between his four sons into Hesse-Cassel, Hesse-Darmstadt, Hesse-Marburg and Hesse-Rheinfels.
This was signed by the elector of Saxony and his son and successor, John Frederick, by George, margrave of Brandenburg, two dukes of Luneburg, Philip of Hesse and.