Tromp had also been suspended after the failure in Shetland, and Vice-Admiral Witte de With was given command. The Dutch convoys being at the time safe from English attack, De With saw an opportunity to concentrate his forces and gain control of the seas. At the Battle of the Kentish Knock on 8 October 1652 the Dutch attacked the English fleet near the mouth of the River Thames, but were beaten back with many casualties. The English Parliament, believing the Dutch to be near defeat, sent away twenty ships to strengthen the position in the Mediterranean. This division of forces left Blake with only 42 men of war by November, while the Dutch were making every effort to reinforce their fleet. This division led to an English defeat by Tromp in the Battle of Dungeness in December, while it failed to save the English Mediterranean fleet, largely destroyed at the Battle of Leghorn in March 1653.