The Greek Phalanx (750 BCE)
Technically the Phalanx is the formation. The individual soldiers were armed with the “Sarissa,” a long heavy spear, and a shield, but a phalanx is most notable for being greater than the sum of its parts. The Greek soldiers would stand in rigid formation, their shields interlocked to protect not just themselves, but perhaps most importantly the man to their left. The phalanx conquered the Mediterranean by moving as a single unstoppable armored unit. It was in many ways, the tank of its day, and the fact that we still use the word in modern speech is a testament to its effectiveness.