Argentina invaded the British dependent territory of the Falkland Islands on 2 April 1982 and South Georgia on 3 April. An Argentine military governor, Brigadier General Mario Benjamín Menéndez, was installed. The Conservative government of Margaret Thatcher quickly assembled a task force to retake the islands, with the first elements sailing south on 5 April. British troops landed at San Carlos Bay on 21 May and fought their way across East Falkland towards the capital Port Stanley. On 11 June British forces, by now led by Royal Marines Major General Jeremy Moore, launched their attack on the outer ring of the Argentine Port Stanley defences in the battles of Two Sisters, Mount Harriet and Mount Longdon. After a pause to reposition troops and ammunition, the British launched the 13 June attacks on Mount Tumbledown, a key feature in the defences and attack on Wireless Ridge, overlooking Port Stanley. After taking these positions, the British troops noticed the Argentine forces withdrawing into Port Stanley and began to follow them up.