Bandit and Heir, the Quadrilogy

Twins are conceived deceitfully by an impotent Emperor. The twins are born during the siege of a bandit fortress, and then are separated by the Emperor, who deprives them of psychic power. The twins are reared separately, as Bandit and Heir, and as they become men, their paths begin to cross and clash. After discovering their true origins, the twins are reunited, their empathy link reestablished.