Landgrave Philip had embraced Protestantism in 1524 after a personal meeting with the theologian Philipp Melanchthon.

He had then helped suppress the German Peasants' War by defeating Thomas Müntzer at the Battle of Frankenhausen.

Philip in 1525 had refused to be drawn into the anti-Lutheran league of George, Duke of Saxony.

By his alliance with John, Elector of Saxony, concluded in Gotha on February 27, 1526, he shows that he is already taking steps to organize a protective alliance of all Protestant princes and powers.

At the same time, he unites political motives with his religious policy.

As early as the spring of 1526, he seeks to prevent the election of the Catholic Archduke Ferdinand as Holy Roman Emperor.

Philip openly champions the Protestant cause at the Diet of Speyer in the same year, rendering it possible for Protestant preachers to propagate their views while the Diet is in session, and, like his followers, openly disregarding ordinary Roman Catholic ecclesiastical usages.