|The corvette Immacolata Concezione - the last ship in the Papal Navy|
There were times when the Papal Navy (Marina Pontificia in Italian) was a considerable maritime force of the Papal States. However, as the Papacy had already been confined to the Vatican City after the capture of Rome in 1870 (the final event in the process of Italian unification), Pope Leo XIII is said to have sold off the last ship in the papal navy, the corvette Immacolata Concezione, during his first year in office (1873).
The flag and a scale model of the Immacolota Concezione are now in the Vatican Museum in the Lateran Palace.
An article from 12 May, 1939, published on the Catholic Herald archive page gives some additional information about the fate of the papal yacht:
It is just eighty years since the last flagship of the-Papal Navy was launched on the Thames, according to a recent article in the P.L.A. Monthly.
It is not generally known that there ever was a Papal Navy, and yet the Papal Squadron distinguished itself at the Battle of Lepanto. But by the time the last Papal flagship was built in 1859, Pius IX needed nothing more formidable than a private yacht and a fisheries protection vessel.
"The steam corvette Immacolata Concezione was a graceful, full-rigged auxiliary ship," states the P.L.A. Monthly, "armed only with eight 18-pounder brass cannons. Cardinal Wiseman and a distinguished gathering of Catholics saw her off from the Thames ironworks at Blackwell.
"After 1870, Pius IX presented her to a house of the Dominican Order at Arcachon for use as a training ship.
She changed hands, first to English and then to French owners, and eventually was lost in the Mediterranean as recently as 1905." It. was frequently the custom for the Papal Government " to buy British."