The 'Prince's Migration was an event in the British Empire local Indian Princes were encouraged to emigrate to Africa.
Great Britain controlled virtually the whole of the sub-continent by the Treaty of Delhi, with the vast majority of the Indian princes who signed the document vassals and servants of London in all but name. Many of them were encouraged by the Colonial Office to immigrate to British colonies in Africa. This would not only collapse the leadership of any nationalist movements (which were starting to emerge in Europe at this time, and Britain, rightfully, believed it would spread to India), but also help settle the major colonies in Africa. Soon, the population of colonies such as Kenya and South Africa doubled with the rapid influx of Indian princes speaking English and in European dress.
This began an astonomical social change. The social structure of the old empire was dying. In an effort to crush nationalistic thoughts and secure dominance over the continent, the British had endangered the old order. Racism still existed but it simply wouldn't do or even make sense. You cannot call a person naturally stupid or inferior when not only do they fight, die and colonise in Britain's name, they settle down and have large families, work hard and become rich and powerful off the profit. By the mid-19th century, British East Africa had a population that was at least two fifths South Asian origin. Many MPs were of Indian extraction. Though the old order was virtually destroyed as equality of race came to the forefront of British policy, it drew the Empire together and began to fuse it in a cohesive whole. The glue of Empire was the Indians.
In many other parts of the Empire, other minorities were given some of the same rights: The Aborigines and Maori in the Australasia, the Native Americans in the colony of Canada and modern day Assiniboia, and the many hundreds of African tribes in the Dark Continent. Although the white's in British North America protested against this treatment of the locals, and that same tension lead to the creation of Assiniboia in 1874, overall the policy was successful; British control of Africa was strengthened, no nationalist movements of any worrisome strength could be established for decades, and, by the end of Queen Victoria's reign, the Colonial Government Act allowed all citizens of the British Empire (not including the Dominions; Canada, South Seas, etc.) to be able to send representatives to the House of Commons. However, the rise of the Imperial Socialist Party after the Second Global War ended all the rights the colonies had, and after the British defeat in the Third Global War, most of the territories were divided between France, Persia, Egypt or given outright independence.