Diego met his magical soulmate, Beatrix Neck, fresh out of Highborn. They became a couple and she was pregnant within a few months before she met Bosley and Aldrich, who would become her second and third lovers.
Beatrix wasn't wealthy or titled, and Diego was the heir to a Dukedom, so naturally, his parents were not thrilled about welcoming a woman like this into their house, especially since Diego intended to hand his title and estate over to her, ending the Calderon legacy.. They demanded Diego keep Beatrix as a side piece, while marrying someone else that they found acceptable, and only the children from that union would be considered heirs to his title. He told them to piss off, and left his family behind, which caused him to be disinherited.
Beatrix gave birth to a single child, Jaz, when they were almost certain she would be having twins.
When Jaz was still young, Diego was mysteriously murdered.
Neck-Romancer: It's a Wonderful Jaz