spartan231490 said:
1) Tied for first place, I suggest the shield and military aircraft. The shield led to the advent of phalanx fighting, which led to highly advanced tactics. Phalanx fighting allowed alaxander the great to conquer a huge amount of territory and ironically allowed the greeks, most notably the spartans, to defeat the invasion of persia.
I've gotta say in my view the phalanx didn't involve much tactics.
The whole point of the phalanx warfare was it's simplicity- each and every male citizen with a spear and shield could partake without knowing much about warfare at all. Greek on greek land warfare during this era involved two huge masses of men colliding with each other. There wasn't much tactical flexbility at all and formations were too rigid imo. It's strength lay in the fact that any able male citizen, though by himself pretty useless, became a fearsome force to be reckoned with in a phalanx with other citizens.
Plus though the phalanx played a huge role in the persian wars, so did the greek xenophobia, propaganda and the athenian navy. Also I don't see the irony in the greek victory over the persians during the invasion.
Even in the Pelopponesian wars the phalanx warfare wasn't very tactically versatile or complex; the more experienced and stronger mass of hoplites won the battle pretty much every time. Even in Alexander's time and the hellenistic to roman age the phalanx' job was to engage the main enemy bulk and hold the line, whilst the cavalry went for the throat which was pretty much how Alexander won all his battles against the persians.
I'm gonna say the following deserves a mention for the greatest weapons in history.
Propaganda. From ancient times to modern day, propaganda proved itself to be a great tool and weapon in wars. Though it can't kill enemies, it can sure demoralize them and strengthen the resolve of your military and citizens.
The roman legion. I don't think you can really point out just a single weapon or component of the legion and claim it was great, as it relied on the others to function to its fullest potential. The gladius without the discipline and shield would be nothing more than a short sword, and the pilum would be nothing more than a javelin. However, together it made one of the greatest war machines of the ancient times and truly revolutionized warfare. The first professional army, amazing array of tactics at its disposal and the genius use of engineering in warfare.
Actual physical weapon wise, I'm gonna say the musket. The likes of a longbow, crossbow and swords generally required experienced and skilled hands to be truly deadly. The musket completely levelled the playing field.