Built at the Monfalcone Shipyard, the Sauro-class III Series submarine Giuliano Prini (S 523) was laid down on July 30, 1987, launched on December 12, the same year, commissioned in the Italian Navy on May 17, 1989.

Designed in the 1980s as "hunter killer" to contrast the underwater threat from the Soviet bloc, the boat has undergone significant upgrading and technical-operational improvements to meet the operational requirements of the new millennium.

Home-based in Taranto, the vessel is capable of performing covert surveillance operations, control and defense of strategic sea areas, detection, shadowing, attack on submarines and surface ships, support to special operations and intelligence gathering.

Submarine Prini is the first boat named after WWII hero Giuliano Prini, awarded the Gold Medal of Military Valor with the following citation:
"Since the outbreak of the Second World War, the young submarine commander showed his willingness to fight in high – risk areas. In command of his boat, he prevailed over the enemy six times during three exhausting missions in the Atlantic, sinking more than 43,000 tons of enemy armed steamers.
His enthusiasm and fighting spirit combined with seamanship, enabled him to gain fame as a gallantry commander, always pursuing the most challenging goals and confronting the most daring and risky actions with the hero's qualities of faith, peace of mind and calmness.
During his last heroic mission against a powerfully escorted convoy, he managed to sink two vessels and set fire on a third one.
In keeping with the highest naval service traditions of attacking in all circumstances, he disappeared with his submarine in the impetus of the battle, in an aura of glory, gallantly giving his life in the service of his Country and the Navy"

The Crest

The crest is a tribute to the acts of valor and heroism linked to the boat's name. The silhouette of the submarine is depicted while sailing on surface at high speed. In the center, a young girl, symbolizing Italy, appears on the horizon with her hair loose and a towered crown, symbol of patriotism, on her head. In the lower part the inscription of the motto:
"Quid Possit Itala Virtus" rises from the waters and alludes to the memorable valor of Commander Prini. The submarine's name and optical badge (SMG G. PRINI – S 523) are inscribed on the top. The three stars shining in the sky stand for the constellation corresponding to the commander's date of birth.