You've escaped from servitude on a tobacco plantation and made your way to an island outside the reach of the law. Due to your wit and sophistication, the buccaneers on the island elect you their leader. You rule, for now. The question is, how to stay in power, and how to become fabulously wealthy?
To keep your followers happy, you'll need to supply them with wine, women, food, and a few other essentials like gambling. If you aren't a good provider there are plenty of other buccaneers who want your job and your fancy palace. But how can these things be paid for? The island has no industry or agriculture or anyone living here willing to do an honest day's work. The obvious answer is piracy.
The seas off your little isle are teeming with unprotected and foolish merchant ships just waiting to be plundered. Piracy makes your continued rule possible: it gives you funds to spend on expansion; it brings back captives to work in your taverns, gambling halls, industries, and farms; and most important, it puts money in the hands of your buccaneer followers. As long as they have money to spend, and a bar to spend it in, they'll continue to do what you order--most of the time.
When you command enough pirates, the great powers of the 17th Century may bid for your services in a war. Be careful. Some of your pirates might not feel secure working for the nation that made them outlaws. Other pirates might decline to serve against their homelands. And of course, all pirates fear an encounter with a well-trained naval vessel of England, France or Spain. These battles are risky and some pirates won't return. On the other hand, defeating a naval vessel means lots of new pirate recruits and probably new cannons and other plunder.