Theft of Swords is the first book Michael J. Sullivan wrote, and self-published, about 7 years ago. Chronologically, it takes place after the events of The Crown Tower and The Rose And The Thorn, so you may want to read those first.
Swashbuckler. It's the word that comes to mind whenever I tried to describe the whole Riyria tale (what I've read so far, at least). Hadrian's a nice-guy mercenary with a heart of gold, and Royce is a no-nonsense thief/assassin who you just don't mess with.
The book is actually two separate stories.
The first, The Crown Conspiracy starts with the pair taking a job to steal a rapier from Count Pickering, to ensure that he is unable to kill the client in a duel the next morning. What follows is a series of unfortunate events (and plot twists!) that land our heroes in a magical prison, helping a 900-year-old handless wizard, going up against an ancient church bent on world domination through political manipulation.
It's quite a ride.
Along the way, we get to spend more time with Alric, son of King Amrath of Melengar, dive deeper into the history of Novron and Maribor (mythology for the win!) and travel the face of Sullivan's finely detailed world, Elan.
The second story, Avemparth continues to peel back the centuries and peer into the history of Elan, the human kingdoms and the Elvish lands. Thrace, a woman from a small backwoods town, travels to Colnora to hire Royce and Hadrian (on the advice of "Mr. Esra Haddon"). The job is simple: steal a sword from a tower so that her father can defeat a creature that is terrorizing their village.
But things are never simple in Elan, and our heroes soon find themeselves once more in the middle of a struggle between the Church of Nyphron and, well, everyone else. Avemparth (the tower) is Elvish, of course, sitting on the Nidwalden river between Elvish and Human lands. It's a place of magic, where an artifical creature has broken free and continued its pre-programmed routine of murder and mayhem. Add a Dwarf into the mix, a medieval contest of skill and a power-hungry bishop, and you've got the makings of a truly riveting story.
tl;dr; Recommend, if you liked Chronicles, love intrigue, and want to know what happens next.