Throughout the summer, William assembled an army and an invasion fleet in Normandy. Although William of Jumièges's claim that the ducal fleet numbered 3,000 ships is clearly an exaggeration, it was probably large and mostly built from scratch. Although William of Poitiers and William of Jumièges disagree about where the fleet was built – Poitiers states it was constructed at the mouth of the River Dives, while Jumièges states it was built at Saint-Valery-sur-Somme – both agree that it eventually sailed from Valery-sur-Somme. The fleet carried an invasion force that included, in addition to troops from William's own territories of Normandy and Maine, large numbers of mercenaries, allies, and volunteers from Brittany, northeastern France, and Flanders, together with smaller numbers from other parts of Europe. Although the army and fleet were ready by early August, adverse winds kept the ships in Normandy until late September. There were probably other reasons for William's delay, including intelligence reports from England revealing that Harold's forces were deployed along the coast. William would have preferred to delay the invasion until he could make an unopposed landing.