In a further attempt to relieve pressure on the Netherlands, he was next ordered to take the fight against the French to the Caribbean. He arrived off Fort Royal, Martinique aboard his flagship on 19 July 1674, leading a substantial force of eighteen warships, nine storeships, and fifteen troop transports bearing 3,400 soldiers. However, although his destination was supposed to be secret, news had leaked out and had been sent to the French governor, which allowed the greatly outnumbered French defenders time to prepare a strong defensive position. When the Dutch troops went ashore the next day to attempt an assault on Fort Royal, they suffered significant casualties in their attempt to reach the French fortifications, including the loss of most of their senior officers, and they returned to the fleet with 143 killed and 318 wounded, compared to only 15 French defenders lost. With the element of surprise lost, and with disease spreading aboard his ships, De Ruyter decided against further attacks and returned to Europe .