Black tea was first developed during the late Ming Dynasty (before 1644). All true tea comes from the leaves Camellia sinensis bush.
It is how the leaves are processed that determines which type of tea it becomes.
Black tea goes through a process which starts with drying, called oxidization. Tea leaves intended to be processed as black tea are often macerated during this oxidation process which allows more of the tea leaves to be exposed to air and fully darken. It is this process that produces the dark, full-bodied cup with the strong, rich flavor for which black tea is known. Black teas are the only type of tea to be fully oxidized.
Black teas do contain caffeine. Typically, they contain about half the caffeine of a cup of coffee. It is important to note, though, that the actual amount of caffeine in black tea varies from tea to tea.
There are many health benefits to enjoying a good cup of tea regardless of the type of tea, but perhaps the best benefit of all comes to the soul. We embrace William Gladstone's famous poem and give a resounding yes to each line.
"If you are cold, tea will warm you;
if you are too heated, it will cool you;
If you are depressed, it will cheer you;
If you are excited, it will calm you."