sentences:  Upon attaining his majority, he married Isabella, daughter of Richard de Clare, 6th Earl of Hertford, by second wife Maud de Lacy, in 1258.William's mother was a first cousin of Eleanor of Provence, queen consort of England, and it was through the latter's influence that the marriage was arranged.In his first years, William looked to exert his power in the southern Piedmont, as many of his predecessors had tried, fighting the independence of the communes of Alessandria and Asti.