Tea (according to Chambers Encyclopaedia) was introduced to the British Isles at Thomas Garroway's Coffee House in London in the 1650s. Coffee remained a popular drink, along with tea, until a series of blights affected coffee production, the major blow coming with the destruction of the coffee crop in Ceylon in the 1870s. Thus, for many Britons, tea was a second choice.
Most English tea came from China, the first shipments arriving from India in 1839.

I prize one sentence in Chambers essay on tea: "It was a factor in the unfortunate chain of events which culminated in the American was of independence."

Unfortunate for the British, but certainly not for the Americans. Who knows, Obie and his compatriots may someday achieve full independence as well- no more royalty on stamps (dump the last printing in Hudsons Bay), no more Governors General spending fortunes on needless travel and receptions, abandonment of the fiction that British royals mean anything over here.
Just another viewpoint from a western Canadian, where tea is almost never seen in restaurants.