AFTER T H E CONVOY in March 1942 a few special cargoes reached Malta in submarines and in the fast minelayer Welshman, but the fortress had to wait till the middle of June for the next attempt to supply it on a large scale. This was chiefly due to the unceasing assaults on Malta from the air; as Admiral Sir Henry Harwood, the new Commander-in-Chief, Mediterranean, wrote in his report of the operation in March, " It is evident that before another Malta convoy is run, air superiority in the island must be assured." Accordingly, strong reinforcements of fighter aircraft were sent to Malta, flown off from the Eagle and U.S.S. Wasp. By the middle of May the bombing attacks had slackened, largely as a result of great air battles on the 9th and 10th, when the enemy lost heavily both in bombers and in their fighter escorts; more British fighters arrived early in June.1 In these improved circumstances it was decided to make another attempt to supply the island, and a double operation was planned: a convoy of six ships from the United Kingdom through the Strait of Gibraltar-Operation " Harpoon"—and another of eleven ships (Convoy M.W.I1) from Egypt-Operation " Vigorous "—the two convoys being timed to reach Malta on consecutive days. This, it was hoped, would divide the attention of the enemy between the two convoys while they were on passage. Mining of the harbour approaches had greatly increased since March2 (when the Southwold was lost), and as Malta was almost entirely without resources to deal with this danger, it was arranged that minesweepers should accompany the convoys to sweep them into harbour, and subsequently to strengthen those stationed at Malta.