The East India Company (EIC) has played probably the most significant role in modernising the Indian Army to a great extent during its reign in India. It`s a well known fact that the EIC was actually the company through which the British rulers came to India and ruled the country for near about 200 years, in succession. Before the EIC came to India, the Indian Army was a bit in a messy and undisciplined condition, though there were some efforts to modernise it. The EIC brought some great European military techniques to India, along with the highly improved weapons. In a sense Indian army during British rule was hugely modernised.

The military success of the Indian army during British rule was actually the result of two great innovations. The first one was within the military and it was the professionalisation of logistics. In fact the mobility of the EIC Army, along with the development of militarily powerful infantry units, helped the British to defeat any other regular army in India. The EIC Army was also capable of defeating the irregular and guerrilla forces that continued to fight the British after the regular armies had been defeated. The British rulers did another thing, once it captured the entire India and they actually merged the Indian Army of their captured areas, along with the EIC Army and the combined Army was huge. During that period, the area within which any army could fight a battle in India was in large measure was determined by how far it could march from its base and still feed itself. The area an army could control was also determined by how long an army could besiege an enemy fort and still feed itself. The modern logistics system that the British rulers followed helped the EIC Army to be fast and powerful and also to extend their reach against other big armies, and also against lightly armed, very mobile local forces.

After merging of the EIC Army and the Indian Army the British rulers gave their attention in modernising and improving the skills and techniques of the Army. A number of steps were taken to improve the qualities of the Indian army during the British rule. The famous British commander, Robert Clive, who defeated the mighty force of Nawab Siraj-ud-daulah in the Battle of Plassey, divided the Bengal Army into three brigades. He did so because if he would deploy the entire army in any one area, it was likely to lead to grain shortages and also increase in the price of food. It would also lead to starvation for the local peasants, and unrest among the sepoys who had to pay for their own food. About thirty years after this move by Clive, the EIC (East India Company) army achieved the capability to move and feed an army of eight thousand infantry. However, the indigenous Indian army of the Indian kings never let the British to expand their territory easily. Facing the protest from the Indian kings, the British rulers followed the way of aggressively expanding the area of EIC control.

The Nizam of Hyderabad managed a large army during the British period and there were considerable number of foreign officials involved with his army. He used the American, Irish, and particularly French officers for training his soldiers and the number of European-trained troops of Nizam was increased from fifteen hundred men in 1792 to eleven thousand in 1795. The number was eventually increased to fourteen thousand. The Nizam was also training his army according to the modern European military techniques. The famous Indian ruler, Tipu Sultan of Mysore was another great emperor, who possessed a powerful army and he made a lot of complications for the British Army. Apart from the Nizam of Hyderabad and Tipu Sultan, the Sikhs in the Punjab also modernised their armies during 1830s and they became able to defeat the British army at Mudki in 1845, as well.

The British rulers did a good job by recruiting the Indian soldiers into the British army and they could do so, because a large number of Indian soldiers became unemployed, as their leaders were defeated by the British army. The British rulers actually imported a new and more powerful mode of military organization. They started to pay their soldiers on a regular basis and though the pay package was not better than that of the Indian rulers of that time, the British maintained the regularity, strictly. That gave the soldiers interest to stay for a long term in this profession. There was an influence of the Indian social system in the military organisation of India during the British period and the British rulers separated the Indian soldiers to professionalise them.

The Indian army during British rule, formed the soldiers into companies and battalions and the soldiers were commanded at unit level by the Indian officers, who came from the soldiers` respective social groups. The British did so, because the need to have military subunits that spoke the same language and that were commanded by officers, who also spoke the language of the men and understood their social customs, was basic. They formalised this into a system of recruiting men for battalions and regiments exclusively from single sub-castes, like the Jats or Dogras. The British also used to recruit soldiers for given units from the same villages year after year. The rulers also gave the soldiers the conditions of full-time or long-term service.

The EIC Army was mainly composed of three different divisions or armies, named the Bengal army of the Calcutta Presidency, the armies of the Bombay and the Madras Presidencies in India. Each of the armies had their respective different internal organizations and the organisation affected their levels of professionalisation. In spite of being named as the Bengal army of the Calcutta Presidency, most of the soldiers of this army were not coming from Bengal; rather they came from the neighboring areas of Oudh and Bihar. Both the areas had had large local armies before the British period. On the other hand, most of the recruitments into the Bombay army were made from the large military populations of the Punjab, Oudh, and Rajputana. The professionalisation of the British Army actually meant more attention to military discipline and performance of military functions.