Prisoner of Xendor is a canonical novel detailing the adventures of a a young man who looks identical to the Viceroy of Alderaan who was imprisoned by the fallen Jedi Xendor. It is set 24,500 years before the Battle of Yavin.
It is a time of danger and other not-very-safe-things-that-might-kill-you in the Galaxy! The Viceroy of Alderaan has been forced into imprisonment by enforcers by forces aligned with forces of the dark side of the Force! However, there is hope for the hopeful hopefuls who, filled with hope, aspire to bring hope to the hopeless! The Viceroy has a lookalike who has agreed to fill in for him to prevent the planet from descending into chaos! An all new exciting addition to the Star Wars universe! An adventure so awesome that the only way to describe it is an overabundance of exclamation points! Excitement! Yaaay! C'mon! Buy this book so Del Rey can make more money! Yaaay! Star Wars! Exclamation points! Wheeee!
Prisoner of Xendor was well received by the Star Wars fan-base, members of which with their usual fawning worship of everything Star Wars praised it as the best addition to the Expanded Universe since the book preceding it. Their enthusiasm was matched only by the jaded loathing evinced by the more intemperate fans, all of whom were at least ten years older. These elders, being older and thus aware of real-world literature, were able to see the whole book was in fact no more than a horrible pun on The Prisoner of Zenda.