He was born Pietro Geremia Celesia in Palermo in 1814, the son of Lancellotto Celesia, Marchese of Sant'Antonino, and Giuseppa Caruso Azzolini. Through his sister, Donna Francesca Paola Celesia, he is Gisella Giovenco's 2nd great-granduncle. His paternal grandmother was Isabella Renier, from Venice[1]. As a teenager, he felt called to become a monk of the Monastery of San Martino della Scala in his native city, which belonged to the Cassinese Congregation of the Order of Saint Benedict. He was received as a candidate of the monastery in 1833 and, at admission into the novitiate, he was given the religious name of Michelangelo. He made his solemn profession on 15 January 1835 and was ordained to the priesthood on 24 July 1836.
Celesia died in Palermo the following year, at the age of 90, at which time he was the oldest living cardinal. After lying in state in the Palermo Cathedral, he was buried in the church of the Capuchin friars in Palermo. His remains were transferred several years later to a side chapel of the cathedral.