However, the Republic gained great victories at other locations. The war with France had closed the Spanish Road for Spain, making it difficult to bring up reinforcements from Italy. Olivares therefore decided to send 20,000 troops by sea from Spain in a large armada. This fleet was destroyed by the Dutch navy under Maarten Tromp and Witte Corneliszoon de With in the Battle of the Downs of 31 October 1639. This left little doubt that the Republic now possessed the strongest navy in the world, also because the Royal Navy was forced to stand by impotently while the battle raged in English territorial waters.