St. Patrick was never a pope. He was a bishop.
Was Patrick the bishop of Rome? No. That would have made him the pope and he was never a pope.
Pope Celestine
The pope's church is St. John Lateran. As the bishop of Rome this is his Cathedral. As pope, his church is St. Peter's Basilica.
Ambrose was a convert to Christianity and governor of Milan, Italy, before he was named bishop,
St. Augustine of Hippo's mentor was St. Ambrose, the Bishop of Milan. Ambrose played a significant role in Augustine's conversion to Christianity and guided him in his theological studies and spiritual growth.
There are several saints and bishops buried at the Basilica of St. Ambrose in Milan, Italy. However, the most notable person buried there is Saint Ambrose himself, who was the bishop of Milan in the 4th century.
Saint Ambrose, also known as Ambrose of Milan, was a renowned bishop in the early Christian church. He was known for his theological writings, defense of the faith, and influence in the Church. After his death, he was venerated as a saint by the Catholic Church for his contributions to Christian doctrine and practice.
St. Ambrose
St. Athanasius was one of the four fathers of the church, along with Sts. Jerome, Ambrose, and Pope Gregory the Great.
St. Eugene de Mazenod became a bishop in Marseille, France.
As pope, his church is St. Peter's Basilica in the Vatican but as Bishop of Rome, his church is the Basilica of St. John Lateran in Rome, Italy.