What Is Catapults?

Caterpoles were used in the 5th century BC, like 480 BC or whatever they just say. It's this instrument on which you put these massive stones and then you fling the stones at fortifications. We know that there is no evidence of warfare from the entire Saraswati Sindhu phase of Indian history. But a civilization that can develop all these advances in technology can certainly develop a catapult.