Saint Peter is shown holding the keys of the kingdom in his hand, given to him by Jesus, signifying his leadership (Matthew 16:18-20). In bronze to his left are clergy of the Western Church and, on the right, clergy of Eastern Rite Churches. Thus, this altar represents the universality of the Catholic Church, because both are united under the Pope and retain the Apostolic succession that began with Peter. Interestingly, Peter was the patron saint chosen for the first Pro-Cathedral, St. Peter's Church, built when Baltimore became the first diocese in the United States, in 1789.