In the two months of fighting that followed, 255 British and about 650 Argentine servicemen were killed, along with three Falklands civilians, before Argentine forces surrendered.
Argentina still claims sovereignty over the islands, which it calls Las Malvinas.
Here are the key dates in the conflict.
Thirty years ago Argentina invaded the Falkland Islands, which had been held by Britain for 150 years, leading to a short but bloody war.