Son of the Lord Protector, brother to Mara and member of the royal house within the tower on Eldred's planet. Tavius conspired with Otho to end his father's reign early. In exchange for the title of Lord Protector, Tavius would give Mara to Otho in marriage. But Otho broke their agreement when he was given an Ancient gene therapy vial from John Sheppard. Instead of ascending to the throne himself, Otho took his place.
The Tower - Tavius is dethroned before he can even take the position, replaced by the chamberlain Otho.