left|thumb|198x198px|Fr. Giovanni Maria Mastai-Ferretti teaching to orphans Mastai-Ferretti was ordained a priest on 10 April 1819. The Pope had originally insisted that another priest should assist Mastai-Ferretti during Holy Mass, but rescinded the stipulation after the seizures became less frequent. He initially worked as the rector of the Tata Giovanni Institute in Rome.
left|thumb|198x198px|fr giovanni maria mastai-ferretti teaching to orphans mastai-ferretti was ordained a priest on 10 april 1819 the pope had originally insisted that another priest should assist mastai-ferretti during holy mass but rescinded the stipulation after the seizures became less frequent he initially worked as the rector of the tata giovanni institute in rome