He was born to Luigi Cialdi, of Tuscan origin, and Plautilla Gandini, in a modest family of merchants. He undertook his early studies in his hometown before moving to the Nautical School in
Genoa from 1828-31. He made two trips to America on Sardinian ships, with the
Sardinian flag, first as a ship's clerk, then as captain of a merchant ship that sailed to
Rio de Janeiro. In the late 1830s he was taken into the government service of the
Papal States, initially as a pilot on the
San Pietro while it patrolled the Mediterranean for cases of cholera that was causing many deaths in a Rome at the time. After this he led a mission on the
La Madonna delle Grazie to convey 119 political prisoners to
Bahia as part of a plan to establish a new colony in Brazil. Returning to Rome, he married Emilia, daughter of the engineer who was teaching him hydrology. She died just sixteen months after they were married. ==Pontifical navy==