Guns, Stock, and Tael: Sword of the Bright Lady by M.C. Planck
Jared Diamond’s seminal work, Guns, Germs and Steel, posited that those three advantages are what allowed the Europeans to come out on top of the 15th century world and go on to dominate the globe in the next several centuries. European diseases decimated the New World, and European steel and guns gave them sway over Africa, Asia and the Americas. The reasons why Europe had those advantages and were able to leverage them is the heart of that book. The idea of introducing gunpowder to worlds that don’t have it is one that crops up now and again in genre. Gunpowder is an invention that is a game changer, and yet, it is not one that requires a lot of technology to manage. It’s really a historical accident that it was invented in China and only when it came to Europe became seriously used for warfare. With the technology and materials available to them, there is nothing that wouldn’t allow gunpowder to be used as far back as the Roman Empire or even earlier. The roleplaying game Fvlminata provides a RPG world where gunpowder was invented by Rome in the first century AD. The Island in the Sea of Time series by S.M. Stirling has the time-stranded Nantucketers introduce gunpowder to the late Bronze Age, with civilizations everywhere wanting a piece of that action — and being able to use it, however primitively.