Theresa was a mortal woman, the daughter of Spanish nobleman, Don Diego, with whom Duncan MacLeod fell in love , while studying in Madrid, in 1851. He intended to ask for her hand in marriage, and told his new teacher, Otavio Consone, about his plans. Consone, however, angrily replied that Theresa was not for the likes of MacLeod, that she was of noble blood, and that MacLeod was the son of a foreigner and barbarian. "Forget, her she is not for you." He then told MacLeod that he had already received Don Diego's permission to marry Theresa, and then told MacLeod to leave Madrid or die.