H.M. Submarine Spartan sailed for the Falkland two days before the Argentine invasion of the islands on 30 Mar 1982. Spartan was the first ship to arrive in the island waters and began to enforce the maritime exclusion zone imposed by the British. Spartan sighted Argentine merchant shipping mining the harbour at Stanley, but was not ordered to attack. Spartan was also called off stalking the Argentine aircraft carrier Veinticinco de Mayo, arguably changing the direction of the conflict as the Belgrano was sunk by H.M. Submarine Conqueror. The Spartan went on to provide valuable reconnaissance British Task Force on Argentine aircraft movements and Spartan's presence also ensured that the Argentine Navy would not leave port.