The Church's independence, aided by popular support for the papacy in Italy, enabled various popes to defy the will of the Byzantine emperor: Pope Gregory II even excommunicated Emperor Leo III during the Iconoclastic Controversy. Nevertheless, the pope and the exarch still worked together to check the rising power of the Lombards in Italy. As Byzantine power weakened, though, the papacy assumed an ever-larger role in protecting Rome from the Lombards, but lacking direct control over sizable military assets, the Pope relied mainly on diplomacy to achieve as much. In practice, these papal efforts served to focus Lombard on the exarch and Ravenna. A climactic moment in the founding of the Papal States was the agreement over boundaries embodied in the Lombard King Liutprand's "Donation of Sutri" (728) to Pope Gregory II.