Chariots were considered as one of the major force in the army under Porus. These chariots were made of wooden struts bound together with leather thongs, and drawn by two horses. Each chariot had a driver and a bowman. Some heavier chariots had four horses. Such chariots carried up to six men, of whom two were shield-bearers, two were archers and two were drivers who also functioned as javelin throwers during battles.
The chariots at Jhelum did not fare well as they got stuck in the mud. King Porus himself had come to battle mounted on an elephant. Invaders like Alexander, conquered India adopted its local military customs, and even its civilian culture. New kingdoms and a few alliances were soon formed. But these proved to be woefully inadequate against yet more foreign invaders.
Wars were a prominent feature in the politics and literature of ancient India. Occasionally great kings like Chandragupta Maurya succeeded in subduing and unifying most of the people of India. Manuals of statecraft such as the 'Arthashastra' of Kautilya indicate the prominence of war as an instrument of state policy. This work dates back to around 300 BC to 100 AD.
The 'Arthashastra' is one of the most significant documents of military history ever to be written. It was an exhaustive treatise on the early concepts of government, law and war. It further also covered the composition and structure of armies, the role and function of the arms and services, training concepts and methods, duties of various military functionaries, strategic and tactical concepts, defensive fortifications, leadership and management of large armies.
Under Chandragupta Maurya, Central Asian invaders like the Huns who destroyed and plundered a major portion of the known civilized world were to stand checked. Chandragupta defeated the last of the clan of the Macedonians. They went on to establish the first great dynasty, the Mauryan Empire. Chandragupta added to the extent of the empire. He was the first to maintain a large, permanent standing army.
Bindhusara further expanded the empire. But it was Ashoka who took the Mauryan Empire to the height of its power and glory. The Kalinga war proved to be the turning point of his life. It was after this that Ashoka renounced the sword and took to Buddhism, which he spread far and wide through his disciples and emissaries.
It was during this period that war elephants made an appearance on battlefields. They continued to be used by Indian warriors, right unto the seventeenth century. Although the Mauryan standing army was based on infantry, it had a force of 30,000 cavalry, 8,000 chariots and 9,000 elephants. The cavalry was well trained and was employed to attack from a flank, and for exploiting captured positions.
During advance they protected the front, flanks and rear. In defense they were held in reserve and were used to harass the attacking forces. They were also used to pursue them when enemy offensive was defeated. The principal weapon used with the elephant was the bow and arrow, supplemented with javelins and spears.
Peace was restored by the Mauryan Empire. Subsequent to this, the pacifist culture accompanied the spread of Buddhism from India to Afghanistan, Tibet, Burma, China, Indo China, Japan and the Indonesian archipelago. This had a greater moral bias and preached non-violence. This kind of spiritual 'conquest' lacked any territorial cohesion and political unity to oppose concerted invasions from the vulnerable north-west.
The 'Golden Age' of The Gupta Empire was from 320 to 550 AD. The most significant achievements of this period were in the fields of religion, education, mathematics, science, the arts, Vedic and Sanskrit literature and the theatre. Harshavardhana managed to restore India's glory and North India was reunited once again.
The many years of peace and prosperity began to feel the strain in 1000 AD. By this time, the Indian civilization became complacent. With the onset of the arrival of Islamic invaders, Indian ancient history wrote another great chapter.
The Northern India contended with a new chapter of foreign powers. Meanwhile, the Cholas, projected their regional military might between 985-1054 AD in the southern part of ancient India. Naval ships sailed out from the Coromandal coast, along the eastern Indian peninsula to Sri Lanka directly to the Malayan peninsula, Jawa, Sumatra and Borneo.
Thereafter Chola Kings extended their hold further eastward to Thailand and Vietnam. These conquests were more trade based. These conquests reflected the spread of Hindu culture rather than conquest by the sword. In due course Indian arts, cultural and religious influences spread to these countries where they have survive till date.
Heading back to the north, the Turkish conquest of India developed in a definite pattern. It was a gradual process which began in the tenth century. The Turks commenced by conducting raids across the frontier. These raids subsequently developed into invasions during which the nearest Indian King was defeated in pitched battle.
The first conquest acted as a catalyst for the next one. This process went on into the seventeenth century when the tribesmen of the thick Assam jungles halted the invading forces.