[AlexanderHowl]

The earliest that firearms could have been developed is TL 1, when you have the domestication of animals producing saltpeter (the only component of gunpowder that is difficult to gather in nature, as charcoal can form in forest fires and sulfur can be gathered around volcanic vents) meeting the development of bronze. While you would not have mass produced firearms, it would have not been possible for bronzesmiths to make individual firearms at TL 1. I imagine that iron would have never become that important in warfare, resulting in a divergence of technology at TL 1.

Imagine a world where the New Kingdom of Egypt discovered the secret of firearms and the pharaohs used a monopoly over the trade in sulfur to maintain their dominion. The New Kingdom of Egypt could have survived beyond 1000 BC, and it may have survived for another thousand years. The Egyptian Empire could have sought to control the supplies of copper, sulfur, and tin in the Mediterranean region and, if it succeeded, would have likely prevented the evolution of Ancient Greece and Ancient Rome.