The
Treaty of Speyer, signed at the
Diet of Speyer in 1570, was a peace agreement between the two Hungarian Kingdoms as
Royal Hungary led by
Maximiliam II and the
Eastern Hungarian Kingdom ruled by
John Sigismund Zápolya. John Sigismund abdicated as King of Hungary, however Maximiliam II recognized John Sigismund's authority as "
Prince of Transylvania" and in return John Sigismund accepted Maximiliam II as King of Hungary with vassalage over his principality.