Juan could have been the heir to the throne of Castile.
He had however been born to King Pedro and his mistress Maria Pedilla when they were very young and before they were married.
Maria Pedilla was a nice of Eleanor Pedilla, Ximene’s grandmother and Eleanor had invited him to join her household when the Politics of Castile became totally unstable. As he grew older he earned his keep by becoming Lady Eleanor’s troubadour.
Despite performing this role well he became first cynical and then opportunistic having little regard for the feelings of those he used to pursue his own advantage.
The one he used most was his sister Alyse as he became aware of the opportunities which opened in front of her.