Sun Ascendant (Saga of the Skolian Empire #5) by Catherine Asaro - Paperback

Ascendant Sun is the direct sequel to The Last Hawk, in which Kelric, heir to the Skolian Empire, crash-landed his fighter on the Restricted planet of Coba. He was imprisoned by the powerful mistresses of the great estates—women who, over time, fell in love with him. After 18 years of living in their gilded cage, Kelric finally made his escape.

In Ascendant Sun , Kelric returns to Skolian space, only to find the Empire in control of the Allied forces of Earth—thanks to the upheaval of the Radiance War. With little more than the clothes on his back, Kelric is forced to take work on a merchant vessel. But when that vessel enters Euban space, Kelric finds his worst nightmare realized: he becomes a slave to the cruel Aristos—who subject slaves to torture and sex to provide their ultimate telepathic emotional drug.