With armies of increasing size, and campaigns taking troops overseas for months and years, it became vital to maintain supply-lines to keep them provisioned. However, an army’s movement could be severely hampered by its supply train. It was the Greeks who revolutionised military supply and logistics; they disbanded the legion of attendants and wives that trailed behind every army, and introduced the speedier horse and mule to replace the ox-drawn carts, meaning that the soldiers had to carry more. The creation of standardised coinage also allowed states to provide for their armies in enemy territory; as their money could be trusted anywhere, local merchants gradually evolved into the first military contractors.
