Leo X Excommunicates Martin Luther – What Does This Mean?

On January 3rd, 1521, Pope Leo X carried through on his threat to excommunicate Martin Luther. The proclamation, Decet Romanum Pontificam was little noticed at the time since Luther had been effectively excluded from the church when he failed to retract all his books and reject the teachings the Pope had declared “errors” in the more famous bull Exsurge Domine and had instead burned a copy on December 10 . Luther would later refer to this as the second of three excommunications he had suffered — his friend and monastic superior Johann Staupitz had first released him from his monastic vows, the Pope had now removed his pastoral office, his right to serve as a professor and barred him from receiving the sacraments as a “notorious heretic.” The third would come later that year at a convention of the princes and territories of the Holy Roman Empire in the city of Worms. More about that at its 500th anniversary.

Even still, it took awhile for the document to take effect. It was executed by Leo’s De’ Medici cousin on January 28th. It was sent to Emperor Charles V, then in Worms, on 18 January, but did not arrive until 10 February. The Papal Nuncio, Hieronymus Aleander, made immediate use of its contents, but prevented its publication. The reason is the document excommunicated anyone who supported Luther, including Elector Frederick the Wise and other princes and territories. He feared retaliation from them at a time when the Emperor needed their support. It did not officially take effect until published in October of 1521.

The bull also labels all followers of the teachings of Martin Luther “Lutherans” and declares them all excommunicated and that no sacraments may be performed in the territories that support Lutherans. Called an interdict, this punishment was sometimes effective in bending secular authorities to the will of the Pope and other times not so much. In this case, it was a complete failure, ignored by both supporters and opponents of Luther alike.

Negotiations had already been underway between Elector Frederick and Emperor Charles V to have Martin Luther appear before the Diet of the empire at Worms. These discussions now intensified at set the stage for the next turning point in the history of the Reformation.