Charles, 2nd Earl Grey (1764-1865) was British Prime Minister from 1830 to 1834. He was a great reformer, but best-known for the blend of tea that still bears his name.
According to popular legend, the blend was a gift from a grateful Chinese mandarin. It seems that an envoy sent to China by Earl Grey did the mandarin a good turn (he may have saved the mandarin's life, the details are unknown).
When the mandarin's tasty gift began to run out, Earl Grey asked his tea merchants, Twinings, to match it for him. This blend became the Grey family's long-standing favourite. When guests inquired about it, they were directed to Twinings on the Strand in London, where they would ask for Earl Grey's tea by name.
The Bergamot Orange is the flavouring used in Earl Grey Tea. Oil of bergamot is extracted from the peel of the bergamot orange (Citrus bergamia or Citrus aurantium bergamia), a small pear shaped sour orange, which is cultivated today mostly in southern Italy, but its origins are in Vietnam and Southern China.
Charles, 2nd Earl Grey (Source)
Bergamot orange (Source)