On 2nd April the Argentines invaded the Falkland Islands. Lieutenant Astiz at Leith paraded his men under the Argentine flag and addressed them saying the island was to be called "Isla San Pedro". On 3rd April the Argentines moved onto Grytviken. A sharp engagement followed with the Royal Marines detachment that had been landed by HMS ENDURANCE following the BAS reports. The Argentines lost a Puma helicopter and the Frigate Guerrico was badly damaged, injuries occurred on both sides although no one was killed. South Georgia was taken forcibly by the Argentines.
A strong naval force was assembled at Ascension Island with Captain Brian Young RN in command. The force - HMS Antrim, Plymouth, RFA Tidespring and now joined by HMS Endurance - sailed into South Georgia waters on 20th April. Reconnaissance missions by special forces to determine Argentine dispositions ashore were launched on 21st April. The next day two helicopters crashed in bad weather on the Fortuna Glacier. RFA Tidespring, a large oiler which was carrying M Company (Captain Chris Nunn Royal Marines) of 42 Commando Royal Marines, was despatched well out to sea on 24 April after the appearance of the Argentine submarine Santa Fe. The same day the force was joined by HMS Brilliant (Captain John Coward) sent down from the Fleet off the Falkland Islands. Early in the morning of 25th April the Santa Fe was attacked and abandoned, disabled, at the King Edward Point jetty. A scratch military force of 75 men under command of Major Guy Sheridan Royal Marines was assembled on HMS Antrim and landed by helicopter on Hestesletten with naval gunfire support from HMS Plymouth and Antrim. The Argentine garrison at King Edward Point surrendered without a fight and 137 prisoners were taken in the early evening of 25th April. The small Argentine garrison at Leith surrendered to HMS Endurance (Captain Nick Barker) and Plymouth (Captain David Pentreath) the next day. Captain Pentreath was present when Astiz signed the surrender document on board HMS ENDURANCE.
Information from http://www.sght.org/conflict.htm