The organisation of all Duke William's forces was difficult.  Everything had to be carefully organised so the trip across the Channel could be safe.  William was ready to invade by the middle of the Summer 1066.

Bad weather forced the invasion force to wait, and eventually set sail on 27th September.

Duke William's force made the dangerous journey across the channel, and are said to have landed at Pevensey.  Yet perhaps they didn't land there!