Isabella I was quite an attentive mother for such a busy queen. John, being her only son, had a special place in her heart and she referred to him affectionately as ’my angel’ even when he was being reprimanded by her, John's wetnurse was Maria de Guzman, a member of the powerful Spanish House of Mendoza. It was commonly believed in the fifteenth century that a wetnurse could influence the character of the baby to whom she fed breast milk. Therefore, a healthy woman, with a placid disposition was ideal.