Guido Thyssen was a member of the House of Thyssen, being the son of Otto Thyssen and Deirdre aep Calhall. He married Klaudia Starhemberg with whom he had three children: Edmund, Ramona, and Berengaria.
Guido continued his father's work and bravely defended Kovir's borders, which didn't go unnoticed by King Gerard Troyden. Surprisingly, at a very young age, he was appointed as Margrave of East March. This heightened Guido's (and therefore the family's) status and the king himself trusted him, as this position was almost equal to the king. This also helped him earn the hand of Klaudia.