Brothers in Arms (Vorkosigan Saga)

Miles is having enough trouble keeping his two identities separate -- the charismatic Admiral Naismith of the Denarii Mercenary Fleet and a Vor lord of the Barrayan aristocracy -- when assassination attempts begin. But are his enemies after Miles Naismith or Lord Miles Vorkosigan? The problem of split identities becomes even more confused when a clone of Miles is discovered, in this novel Booklist called "a first-rate sf tale that mixes court intrigue and galactic warfare."