The Indian indenture system was a system of indentured servitude, by which more than 1.6 million workers from British India were transported to labour in European colonies as a substitute for slave labour, following the abolition of the trade in the early 19th century. Although described by colonial authorities as "free" migration, many recruits were deceived, coerced, or kidnapped, leading historians such as Hugh Tinker to characterise the system as a "new form of slavery". The system began with the Atlas voyage to Mauritius in 1834, but early journeys were marked by mortality rates of over 17%, prompting British authorities to impose stricter shipping regulations. The system expanded after the abolition of slavery in the British Empire in 1833, in the French colonies in 1848, and in the Dutch Empire in 1863. British Indian indentureship lasted until the 1920s. This resulted in the development of a large South Asian diaspora in the Caribbean, Natal (South Africa), Réunion, Mauritius, and Fiji, as well as the growth of Indo-South African, Indo-Caribbean, Indo-Mauritian and Indo-Fijian populations. This migration resulted in the formation of large Indian diasporas, including Indo-Caribbean, Indo-Mauritian, Indo-Fijian, and Indo-South African communities. While many descendants celebrate their cultural resilience, historians emphasise the trauma and displacement caused by the indenture system.
Sri Lanka, Malaysia, and Myanmar had a similar system, known as the Kangani system. Indo-Lankan Tamil, Indo-Malaysian, Indo-Burmese and Indo-Singaporean populations are largely descended from these Kangani labourers. Similarly, Indo-East African are descended from labourers who went primarily to work on the Kenya-Uganda Railway, although they were not part of the indentured labourer system.