After the Norman conquest of 1066, Gytha, mother of the defeated King Harold, was living in Exeter and this may have caused the city to become a centre of resistance to William the Conqueror. Another reason for discontent may have been William's insistence that the city's traditional annual tribute of £18 must be increased. After Exeter's citizens rejected William's demand that they should swear an oath of fealty to him, he marched to the city in 1068 and laid siege to it for 18 days before it capitulated.