So the British East India company was founded on December 31st 1600, they would be the main avenue through which the British would gain control of the continent of India. The company in its early years did not focus on actually taking land in India, but rather on setting up trade stations. The first company station appeared in 1611, and another one popped up in the vital port of Surat in 1613. In 1615 the company asked King James I to send a royal ambassador to India, James complied and sent Thomas Roe to be the official English ambassador. This was the start of England's interests in India. The company trade stations began to grow and eventually became their own autonomous little cities. They were communities of European traders that lived self-sufficiently, they even got so big that they started employing European and Indian soldiers to guard the trading stations; an example of one of these massive trading stations would be Bombay, or Goa. It wasn't just the British either, the Dutch and the Portuguese also had many of these trading stations in India, and they proved to be very profitable; which made the European countries wealthier and hungrier for the wealth that India could produce; but at this time the Mughal Empire was still far too powerful for the Europeans to try and gain a bigger share of the wealth.

However, this started to change in the late 1600's. The Mughal Empire became embroiled in the Deccan wars, which sapped its strength, and the European powers like the British began to flex their muscles and sea. They would lord their superior naval power over the Mughals and any other Indian state, the Europeans had the power to seize any Indian vessel and the power to blockade any port they wanted, and they weren't afraid to lord it over the Indians. The tensions between the British and the Mughals boiled over in the late 1680's when a small war broke out between the Mughals and the British. In what became known as the "Child's War" the British governor of Bombay, John Child, seized a bunch of Mughal vessels in an attempt to force the Mughals to stop trading with non Company traders. This plan backfired and the Mughal Emperor, Aurangzeb, stopped all trade with the British and bombarded Bombay. The British East India Company backed down and payed reparations. This event was important because it led to the East India company strengthening Bombay's defences and helping the city grow; which led to Bombay becoming the most important port in Western India. A large amount of Indian trade would now have to go through the Europeans.

Fast forward a few years to 1757, and the battle of Plassey. The British East India company had already established itself as a military power in Carnatic wars, in which the company fought against the French East India company in a proxy war. It featured Robert Clive and his heroics at the Siege of Arcot which led to the East India Company triumphing over their French rivals. But the battle of Plassey was when the Company began to seriously encroach on the continent and when they began to establish themselves as a major player in Indian politics. Some background on the conflict, the Mughal Empire existed in name only. The various governors of the Empire acted as Kings and payed lip service to the Mughal Emperor in Delhi. The ruler of Bengal, a man by the name of Siraj-ud-Daula, attacked and occupied the British city of Calcutta, and went as far as to mock the British as "cowards". Robert Clive was set to take the city back. The British force numbered about 3,000 and was faced with an Indian force that numbered nearly 50,000. Thanks to some well placed bribes to one of Daula's commanders and some clever tactics, the British crushed Daula's army. The Indian elephants were terrified of the British cannons and most Indian units could not stand up to the continuous British volleys. The British only lost about 70 men, and Daula's army was completely annihilated; Daula himself was killed by his commander Mir Jafir (the man who the British bribed). The British retook Calcutta and installed Mir Jafir as the new governor of Bengal. This established the Company and the British as a dominant power on the Indian continent; for the first time they had played king maker and it would not be the last time. The company would eventually annex the entirety of Bengal in the late 1700's.

The next enemy of the British would be the Sultanate of Mysore. They fought a series of wars with the British in the late 1700's; starting in 1766 and endin right around the time of the Napoleonic wars. The Sultanate of Mysore, specifically Tipu Sultan bought large amount of arms from the French and used French mercenaries to train their army. The British fought a series of wars with Mysore, culminating in the Fourth Anglo-Mysore war which saw Tipu Sultan killed while defending his capital, and led to the Company gaining more land and putting a puppet on the throne of Mysore. With Mysore out of the way, the biggest obstacle left for the East India Company was the Maratha confederacy. The Maratha state was founded by an Indian prince named Shivaji, he made his empire through violence and fought brutal wars against the Mughals and eventually the Marathas became the most powerful state in India. But by the time they came into contact with the East India Company, the Marathas had fallen into a similar situation to the Mughals. That is a weak, figurehead king, with governors running their provinces like independent Kingdoms. While the Marathas managed to fight off the East India company in the first Maratha war, the company was persistent and in the next two wars the various Maratha princes would be beaten and either annexed or reduced to puppets. Major battles were fought at Assaye and Argaon, both of which were major British victories. The formal end of the Maratha empire came after the third Anglo-Maratha war when the last leader of the Marathas was captured and forced to retire to a small estate while his territory was annexed. One of Britain's top commanders during the Second Maratha war was Arthur Wellesley, who later become the famous Duke of Wellington.

While the British and the East India Company did not have total control of India, they did own a big chunk of it. Britain would continue to face problems from India notably the Sepoy Rebellion of 1857 which led to the dissolution of company rule in India and the British government stepping in and setting up the British Raj which would last until 1948. So to recap the British domination of India was a slow process. Starting in the 1600's and not being complete until the early to mid 1800's. The British gained control through cunning use of puppet rulers, forceful diplomacy, and the use of force; and that is how they would keep control of India for 200 years.

A few good books on the matter are:

"The Rise and Fall of the British Empire" by Lawrence James

"The Scandal of Empire: India and the Creation of Imperial Britain" by Nicholas D. Banks

"The New Cambridge History of India: The Marathas" by Stewart Gordon