Earl Grey tea is a black tea blend, which gets a distinctive flavor and aroma from bergamot oil. This blend is named after Charles Grey, 2nd Earl Grey, who reputedly received a gift, probably a diplomatic perquisite, of tea that was flavored with bergamot oil. (Bergamot is a fragrant citrus fruit; bergamot oil comes from the rind.) The legend usually involves a grateful Chinese mandarin, but this blend of tea was first made from fermented black Indian and "Ceylon" (Sri Lankan) teas, though over the years many other varieties have been used.
The tea proved so popular in the Prime Minister's drawing room that his tea merchants, Twining's in the Strand, were given a sample and asked to come up with a close match. Twining's sold the first "Earl Grey's tea" in the British market. Their Earl Grey blend includes China tea, Indian Darjeeling, Ceylon, and a hint of Lapsang souchong, a strong, "smoky" black tea.
Twinings also has a similar tea called "Lady Grey" with Seville orange, lemon & bergamot.
"Earl Green" is a popular name given to Earl Grey-like green teas, such as the Earl Grey Green flavor offered by the Bigelow tea company.
Earl Grey tea was the favorite tea of Douglas Adams, author of The Hitchhiker's Guide to the Galaxy series. Fictional characters who preferred the tea include Jean-Luc Picard of Star Trek: The Next Generation and James Bond, Agent 007 of MI6.