Tomorrow, the Stars — Robert A. Heinlein

Merchant Adventurer Nicholas van Rijn in the Second Chronicle of the Polesotechnic Lea gue! Humankind had explored the galaxy: Nicholas van Rijn had bought it. A star wide empire was difficult to run, but the old man was wily and the resources of the Solar Spice and Liquors Company were vast. But sometimes even a conquered world can get just a little out of hand.