The Phoenix Guards by Steven Brust

Set in the same world as Stephen Brust's beloved Vlad Taltos books, The Phoenix Guards is a fantasy rewrite of The Three Musketeers—a swashbuckling tale of adventure.

A thousand years before the birth of Vlad Taltos, the Dragaeran Empire is a hotbed of intrigue, sorcery, intrigue, wild adventure, and intrigue. For those who would be heroes, it is a delightful time to be alive—and an easy place to die.

Khaavren of the House of Tiassa is a son of landless nobility, possessor of a good sword and "tolerably well-acquainted with its use." Along with three loyal friends, he enthusiastically seeks out danger and excitement. But in a realm renowned for repartee and betrayals, where power is as mutable as magic, a young man like Khaavren, newly come from the countryside, had best be wary. His life depends on it. And so does the future of Draegara.