Armies - The Indian Army
At the battle of the Hydaspes King Porus' army, significantly smaller than its enemy, forced Alexander's Macedonians to fight their most difficult battle ever. Porus may have fielded up to 200 war elephants; they disrupted the Macedonian phalanx, claiming a toll of almost 75% in killed and wounded Foot Companions according to Diodorus.
The common Indian infantrist was the archer, armed with a huge bamboo bow as large as a man was tall. There seems to have been nothing wrong with Indian morale. Plutarch records that after some serious initial losses the Indians rallied and kept resisting the Macedonians with unsurpassable bravery. One hypothetical explanation might be that in the Hindu caste society one of the four castes were the Kshatriyas or 'Soldier Caste', which had its specific rules of conduct and behavior aimed at warfare.
Size
Arrian - as well as Herodotus - is notorious for recording Persian armies of impossible size. Arrian quotes a Persian army of 600,000 strong at Issus and over 1,000,000 strong at Gaugamela. However, the largest army of Alexander's time that we have reliable evidence of is that of Antigonos the One-Eyed in 306 BC, counting 80,000 infantry and 8,000 cavalry. Later Roman armies never exceeded this number: about 80,000 legionaries plus 6,000 cavalry were fighting Hannibal at Cannae in 216 BC and that was reportedly the largest army Rome ever fielded. So, the figure of 80,000 seems to be a sort of natural limit to the size of these ancient armies.
The size limit has to do with the simple need to find provisions. As Herodotus writes, the land itself was the biggest enemy of the traditionally huge Persian forces. Ancient armies did not possess trucks like modern armies do, nor could they be supplied from the air. No matter how ingenious their supply system was, they basically had to live off the land. Passing armies consumed the food supply of a country like a swarm of locusts. They could never retrace their steps: they would starve when returning by the same route. Prior to the battle of Issus King Darius left his base camp at Sochi where a battle could have been fought on favorable ground. Why? It is highly feasible that after one month's stay the Persians had no choice but to move on as they were simply running out of food and water.
Ancient commanders tried to keep their armies as small as possible. Though the Persians firmly believed there was safety in numbers, this basic rule would apply to them as well as to any other nation. Smaller armies were also capable of faster marches. The Macedonians did over forty miles a day during the pursuit of Darius in 330 BC. Armies as large as Arrian records - assuming they could survive at all - would have been incredibly slow. King Darius marched from Babylon to his base camp near in Issus within three months - a distance of 1200 kilometres or 750 miles at least. This he could never have achieved with his alleged 600,000 troops, especially as he marched during the heat of mid-summer and the supply of drinking water alone would have been a sheer impossible task.
Added to the armies were the camp followers. For Alexander's army their numbers are assumed to have been one servant or slave for every cavalry man and one for every ten infantry men. In India Alexander's entire entourage is said to have included 120,000 but his standing army at the Hydaspes is still estimated to have been approximately 40,000 strong - about the same number as he started out with in 334 BC.
Written by nick