Tea drinking in Europe appears to have started in Portugal and was only adopted much later in Britain however Britain is now thought of as the tea drinking capital of Europe. This is reflected in our culture, with tea becoming a staple beverage for many British members of the public and for many around the world.
Interestingly enough many different types of tea e.g. black, white, oolong and green are made from this one species. The leaves are the most commonly used part of the plant and depending on the process used varying levels of oxidation can be attained, giving them a different flavour and colour.
Camellia sinensis
For a popular history of Tea and its spread arount the world try reading the UK Tea Council account.