Indian diaspora
Non-Resident Indian, or NRI for short, refers an Indian citizen who has migrated to another country. Other terms with the same meaning are overseas Indian and expatriate Indian. Lately the phrase Person of Indian Origin (PIO) has also gained usage. The chief difference between NRIs and a PIOs is that the former are direct emigrants from India, where as second and third generation NRIs are referred to as PIOs.
There is a huge PIO population across the world.
One wave of emigrants left India and Pakistan during the Partition of India.
The Ugandan Asians, expelled from Uganda by Idi Amin, are a later wave of emigrants.