Greek merchant ship - Your Epic Historian Ancient Greek merchant ships were crucial because Greece's mountainous terrain made land travel hard, forcing reliance on the sea for trade, connecting city-states, and spreading culture, while their "round ships" (for cargo) and "long ships" (for speed) facilitated vital trade in grains, olive oil, and other goods across the Mediterranean, building wealth, sustenance, and a powerful maritime identity that influenced later naval powers like England. #his