When the British came to control the whole island after 1815 they established a quite distinctive imprint on the island's society and economy. this was most obvious in the introduction of plantation agriculture. during the British period coffee took over from cinnamon, but by the beginning of the 20th century, even though coffee had largely been wiped out by disease, plantation agriculture was the dominant pillar of the cash economy. Rice production stagnated and then declined, and Sri Lanka became dependent on the export of cash crops and the import of food. In 1948 it was only producing about 35% of its rice need.

The colonial period also saw major social changes take place. Under the Portuguese and then the Dutch the development of commercial activity in the coastal lowlands encouraged many "low country" Sinhalese to became involved in the newly emerging economic activity. In a process which continued in the early British colonial period, the low country Sinhalese became increasingly westernized, with the widespread adoption of an English education and the rise of an urban middle class, while the kandyan Sinhalese retained far stronger links with traditional and rural social customs. Despite British reforms in 1833 which introduced a uniform administrative system across the whole of Ceylon, wiping out the distinctive Kandyan political system, a contrast between Kandyan and low country Sinhalese persisted into the modern period.

However , an even more significant change took place in the 19th century. British commercial interests saw the opportunities presented for the cultivation of cash crops. cinnamon and coconuts had been planted by the Dutch and became particularly important, but the after 1815 coffee production was spread to the kandyan Hills. Despite ups and downs production increased dramatically until 1875, when a catastrophic attack of a fungus disease wiped out almost the entire crops. It was replaced, particularly in the higher regions by tea.

Labour had already begun to prove a problam on the coffee plantations, and as tea spread the shortage became acute. Farmer has shown how private labour contractors were recruited to persuade labourers to come to Ceylon from the Tamil country of South India. between 1843-1859 over 900,000 men woman and children migrated to work as indetureed labour.

The cost of their transport was ducated from their wages after they had arrived, and they could not leave until they had repaid their debt. Immigration on the scale created a massive change in the ethnic mix of the Highlands, with a qarticularly significant effect on the kandyan farmers, whose land was increasingly hemmed in by the spread of estaes. the indian timals however remained entirely separate frome the Sinhalease, returning to south India whenever possibel and sending cash remittances home