The word for tea on the Indian subcontinent. In the west it generally means a spiced black tea made with milk (masala chai). It is used in numerous languages, derived from Mandarin Chinese chá. The increasingly widespread word ‘chai’ comes from the Persian chay. Both the châ and chây forms are found in Persian dictionaries.
For centuries the Chinese had a monopoly on the growth and export of chai or tea. In the 19th century when in 1841 Arthur Campbell brought seeds of Chinese tea from the Kumaun region and experimented with planting tea in Darjeeling.
Chai or tea originates in human consumption since 2737 BC. Tea made the consumption of water safer, as the water was boiled to eliminate contaminants, and the tea leaves added flavor to the tasteless water. Sugar and milk are 18th century additions originating in Europe.