Harold the usurper?
'Had William arrived on time, then, things might have gone very differently.'
William assembled his fleet in August, planning his invasion in the south at just the same time. Had things gone differently, had the wind blown when expected, William would have probably landed in late August or early September. Then he would have found King Harold of England waiting on the south coast with a fresh army - including not only the thegns of England, but also a large number of mercenaries, and his Danish housecarls.
Had William arrived on time, then, things might have gone very differently. But he was delayed, and in the meantime Harold Hardrada and Tostig landed in Yorkshire. They fought a battle near York, against the northern English. There were heavy casualties, but they succeeded in occupying York.
King Harold of England heard the news, and took just five days to march his army up to Yorkshire, where he defeated the Norwegians in a terrible battle at Stamford Bridge. Harold then returned to York, only to hear the news that the wind had changed and the Normans had landed 260 miles to the south.
Harold marched all the way back down south, with an army composed largely of his household troops and mercenaries. As one chronicle puts it:
'Except for his household troops and mercenaries ... he had very few people from the country.'
On 14 October, he confronted William's army near Hastings.