A Wizard in Mind - Chronicles of the Rogue Wizard, #1

CAN A FREE CITY STAY FREE? THE ROGUE WIZARDMagnus D'Armand, the renegade son of Rod Gallowglass, Warlock of Gramarye, has set out to prove himself twice the hero and liberator his father ever was, and asks his sentient starship to find him a world in need of revolution. But on the lost colony planet of Petrach, he finds far more than he bargained for: a Renaissance-era world of booming commerce, vicious mercenaries, and Machiavellian political intrigue. THE CITY UNDER SIEGEThe wealthy maritime free city of Pirogia's fledgling republic of merchantmen is about to be wiped off the map by an alliance of nobles determined to maintain aristocratic rule by any means necessary.
Worse, the lords are backed by shadowy and powerful off-world organizations interfering with the planet for their own self-serving reasons. Even the Rogue Wizard will need a miracle to keep Pirogia alive and free against such odds!