Imperialism occurs when a powerful country takes control of a weaker one by enforcing diplomacy and using their military. This happened quite often with bigger countries who usually were wealthier and had a stronger military force than the country they're planning to take control over. There are multiple instances where imperialism occurred such as:
Perhaps one of the most significant examples of imperialism was when Great Britain took control of India. India was under imperialism from 1750-1914 by Britain. The French and the British had fought for India in a seven year war and by the end of it, the French were kicked out. Afterwards, the British mostly relied on Sepoy's, whom were mostly Hindu and Muslim. Out of ignorance, the British disregarded their workers customs and religions and smeared the bullets in pork and beef fat which came from animals who are both sacred in the two religions. They rebelled and after fighting for 2 years, they had lost. After, the British Parliament had claimed the entire continent under British power. The British had considered India to be a "model colony". They used raw materials found in India, that were sent to Britain to be made something and after was distributed right back to Indian markets.
Sepoy's were under employment of the British.
Another example of Imperialism is when Spain took control of Argentina from 1502-1810. The Spanish were in search of "Silver Mountains" which obviously weren't there. Yet, the Spanish stayed. The Natives fought for land vigorously and were doing good until Buenos Aires was securely established in the 1600's. Buenos Aires succeeded until European diseases were introduced and it was banned from trading with anyone but Spain. Spain's king was eventually captured and his vice royalty exceeded him. Argentinians disliked the new ruler and started to vote in their own people and had elected new rulers.
Another example of imperialism is when Portugal took charge of Brazil. Portugal had many advantages over Brazil such as wealth and transportation and even a government making Brazil more or less vulnerable. Brazil could have avoided imperialism if they had a unified army. Portugal wanted Brazil for more territory and agricultural advances. Portugal got to Brazil in 1822 and from there, their empire just expanded. If anything the Portuguese helped Brazil. When Brazil was captured, there was no government and the Portuguese did no harm. They taught the people about trades and established a government, and they also gained independence
The last example is the imperialism of Chad. At the time, France controlled Chad and had defeated them in 1913 making it apart of the French equatorial Africa. The French was desperate for more wealth and territory making Chad a country of desire because of the raw cotton available. Although many Africans were against imperialism, it was beneficial in someways because it eventually introduced schools, roads, and they were given the right to elect representatives.