During the Napoleonic Wars, Great Britain, fearing that French control of the Netherlands might deliver Sri Lanka to the French, occupied the coastal areas of the island (Ceylon) with little difficulty in 1796. In 1802, the Treaty of Amiens formally ceded the Dutch part of the island to Britain and it became a crown colony. In 1803, the British invaded the Kingdom of Kandy in the first Kandyan War, but were repulsed. Under the Treaty of Upcountry (Udarata Givisuma), signed between  the chieftains of Kandy and the governor Robert Brownrigg on 2nd of March 1815, the entire country lost its independence and became a British colony.

Soon the chieftains realised that the British would not honour the Treaty as agreed. The first uprising (called Wellassa Uprising) started in 1818 and was mercilessly suppressed. Used, resulting in revenge in the form of the peasantry stripping of their lands by the Wastelands Ordinance, a modern enclosure movement, and reduced to penury, by the British. The British found that the uplands of Sri Lanka were very suitable for coffee, tea and rubber cultivation. By the mid-19th century, Ceylon tea had become a staple of the British market bringing great wealth to a small number of white tea planters. The planters imported large numbers of Tamil workers as indentured labourers from south India to work in the estates, who soon made up 10% of the island’s population. These workers had to work in slave-like conditions living in line rooms, not very different from cattle sheds.

The British colonialists favoured the semi-European Burghers, certain high-caste Sinhalese and the Tamils who were mainly concentrated in the north of the country. Nevertheless, the British also introduced democratic elements to Sri Lanka for the first time in its history and the Burghers were given degree of self-government as early as 1833. It was not until 1909 that constitutional development began, with a partly elected assembly, and not until 1920 that elected members outnumbered official appointees. Universal suffrage was introduced in 1931 over the protests of the Sinhalese, Tamil and Burgher elite who objected to the common people being allowed to vote.