Francis Chant, known as Frank, is the son of Conrad Chant, oldest of three magically talented brothers who live in the world of Chrestomanci.
Francis and and his cousin Christopher Chant met when they were both young boys, when Christopher came to stay with his family during holidays. Neither boy liked each other much. Christopher felt that Francis was a "stuck-up pratterel" and Francis felt that Christopher was quite useless as he appeared not to be able to do magic. (The Lives of Christopher Chant)
Frank grows up to marry his first cousin, Caroline Chant, who is the daughter of the youngest brother in the same family.
Although the current Chrestomanci Christopher Chant is the son of the middle brother in the same family, the family members don't seem to meet up that often. Chrestomanci writes to Frank, generously offering to keep their children from inheriting any magical powers, which can be somewhat dangerous with that much magical inheritance involved. Frank is insulted by the offer, and writes back something rude. When later he discovers that his daughter Gwendolen appears to be somehow pulling power from his son Eric, Chrestomanci writes back that he doesn't intend to involve himself any more in their affairs, given how obnoxious Frank had been about his earlier offer.
Shortly after that, both Frank and Caroline are killed in a pleasureboat accident, leaving their children orphaned. This begins the events of Charmed Life.