The Warlock in Spite of Himself (Warlock, #1)

Rod 32, ugly, becomes knight Gallowglass to save lost colony Gramarye for galactic democracy, his science mistaken for warlock power. Identical advisers alienate nobles from Queen Catharine, who aids beggars and witches, yet exiles loyal Lords, uncle Loguire and son Tuan. More help comes from his lover Gwen, computer Fess inside iron horse, Big Tom, dwarf Brom, ghosts.