Treaty of San Germano
The Treaty of San Germano was signed on July 20, 1230 at San Germano, present day Cassino, between Holy Roman Emperor Frederick II and Pope Gregory IX. A Dominican named Guala was responsible for the negotiations.
After the treaty was signed, Guala became the bishop of Brescia. Based on the terms of the agreement, Frederick's forces ceased to occupy portions of the Pontifical States. Moreover, all papal possessions in Sicily were restored to the Pope.