There is always more to be said, but you may be interested in my previous answer to How did tea become the signature drink of Great Britain? Tea isn’t grown there.

Chinese tea was first imported to England around 1650, during the Interregnum, and was originally served in coffeehouses; Samuel Pepys didn't have his first cup until September 1660, implying that it didn't immediately have the popularity of the more highly-caffeinated coffee or cheap ale. When Catherine of Braganza married Charles II in 1662, she brought a love of tea with her - either something personal to her or simply something she carried from a culture more interested in the beverage - and by serving it at court, she was able to elevate its status among the elite, which eventually trickled down. By 1689, it was popular enough that the East India Company found it profitable to import tea themselves alongside the spices that were their more traditional cargo. It's likely that the drink/plant's Asian origin also helped make it fashionable: during the second half of the seventeenth century, chinoiserie (basically, "Chinese stuff, or Western stuff made to look Chinese") was a desirable luxury.

By the middle of the eighteenth century, coffee/coffeehouse culture was waning in England, and tea had replaced it, with consumers going to pleasure gardens like Vauxhall and Ranelagh to drink it; the price had still dropped enough that middle-class families could afford it, even if not the best stuff. It also had come to have a reputation as healthful and improving to the mind and body, which translated into the metaphorical body of British people as a whole, and therefore made a group of people drinking tea regularly more calm and sober than groups that didn't. In the early nineteenth century, British colonialists realized that Camellia sinensis could be grown in northeastern India - think Assam and Darjeeling - and Sri Lanka (Ceylon), and started intensely farming it there in order to have a fully "domestic" trade. The rhetoric around this situation - British tea-plantation owners in far corners of the British Empire overseeing the production of this drink, selling it to British East India Company merchants on their fast clippers, bringing it to British dry-goods and grocer's shops, where it was bought by ideal British mothers and prepared for British families - helped to cement it as a quintessentially British beverage regardless of who else might have enjoyed it: consuming tea strengthened the Empire as a whole.

For further reading, I would suggest Tea: A Global History by Helen Saberi (Reaktion Books, 2010) and A Necessary Luxury: Tea in Victorian England by Julie E. Fromer (Ohio University Press, 2008).