The Allies did not fare as well on land. Rommel advanced to Tobruk and beyond in North Africa and Germany successfully invaded Greece and Yugoslavia. German paratroopers overran Crete. In April, British withdrawal from Greece began, meaning that no benefit had resulted from weakening their forces in North Africa. Naval engagements while rescuing British troops from Crete in May cost the British navy dearly. Three light cruisers and six destroyers were sunk; the carrier HMS "Formidable", two battleships, six cruisers, and seven destroyers were damaged. British losses during this operation were greater than Italian losses sustained at the Battle of Cape Matapan. Nonetheless, the British retained control of the sea. However the Germans retained control the air, which severely limited British movements in the eastern Mediterranean.