Fontaine is married. His wife has been described as a "pale beauty". 
At the Court of Equitaine, some consider Fontaine a traitor. Around 960 A.S, an army of roughly 4000 knights, commanded by the Duke of Gasconne, was sent to Avras to retake it. The attempt was failed, the duke was slain and only about 400 knights returned. 
A vampire thrall ? Edit
The army that defeated the Equitan army before the gates of Avras included zombies and other monsters typically found in Vampire Convent armies. This, and other hints, suggest that Fontaine's wife is a vampire. If this, and rumours on the true nature of Gaius Dexon's wife, is true, this could mean that both Fontaine's and Dexion's « queens » are the same being : one vampire queen ruling Avras from behind the curtains since thousands of year.