uring the 5th century BCE, the Achaemenid Empire, or the First Persian Empire, was the largest and most powerful empire in the world. It boasted a large and successful military that had recently conquered large parts of Eastern Europe and the Indus Valley. Emperor Darius I was flexing his considerable might within his sphere of influence, with the Greek city states next in his sights. After Athens and Eretria supported a number of uprisings
