Concordat of Worms, sometimes called the Pactum Calixtinum by papal historians, was an agreement between Pope Calixtus II and Holy Roman Emperor Henry V on September 23, 1122 near the city of Worms. It brought to an end the first phase of the power struggle between the Papacy and the Holy Roman Emperors and has been interpreted as containing within itself the germ of nation-based sovereignty that would one day be confirmed in the Treaty of Westphalia; in part this was an unforeseen result of strategic maneuvering between the Church and the European sovereigns over political control within their domains. The King was recognized as having the right to invest bishops with secular authority in the territories they governed, but not with sacred authority; the result was that bishops owed allegiance in worldly matters both to the pope and to the king, for they were obligated to affirm the right of the sovereign to call upon them for military support, under his oath of fealty. Previous Holy Roman Emperors had thought it their right, granted by God, to name Church officials within their territories and to confirm the Papal election.
