Harold's daughter Gytha married Vladimir Monomakh. Their son Mstislav, Grand Prince of of Kiev, had a daughter, Euphrosyne, by his second marriage, who married Geza II of Hungary.
Geza's grandson, Andrew II of Hungary, had a daughter, Violant, who married James I of Aragon. Their daughter, Isabella, married Philip III of France, and was thus the grandmother of Isabella of France, who married Edward II of England.
Whew!
Ann