On the night of 11 June, after several days of painstaking
reconnaissance and logistic build-up, British forces launched a
brigade-sized night attack against the heavily defended ring of high
ground surrounding Stanley. After 3 Para took Port Stanley, units of 3
Commando Brigade, supported by naval gunfire from several Royal Navy
ships, simultaneously assaulted in the Battle of Mount Harriet, Battle of Two Sisters, and Battle of Mount Longdon.
Mount Harriet was taken at a cost of 2 British and 18 Argentine
soldiers. At Two Sisters, the British faced both enemy resistance and
friendly fire, but managed to capture their objectives. The toughest
battle was at Mount Longdon. British forces were bogged down by assault
rifle, mortar, machine gun, artillery fire, sniper fire, and ambushes.
Despite this, the British continued their advance.