In 52 BC, the Roman Emperor Julius Caesar cut off the food supply of the Gauls led by the “barbarian” Vercingetorix.  By controlling the food supply, he was able to weaken and conquer them (https://www.britannica.com/event/Battle-of-Alesia-52-BCE – https://www.warhistoryonline.com/war-articles/battle-for-alesia-gallic-war.html)  →