18 Thus, advanced in years and worn out by his work, he spoke of himself very humbly: "I am the least and the worst of the representatives which the Roman Catholic and Apostolic Church sent to preach the Gospel.? But he held this Roman mission in high esteem and he enjoyed calling himself "the German representative of the Holy Roman Church." He wanted to be the devoted servant of the popes, and their humble and obedient disciple.
Source: In Hac Tanta (Vatican.va)