Known as “Black Tea” in the West, or "Hong Cha" ("Red Tea") in Asia, black tea is well-known as an afternoon tea for it’s mellow and sweet flavor.
Up until the mid 17th century (Late Ming, Early Qing Dynasty), the only teas that were being consumed in China were green (unoxidized) and oolong (semi-oxidized) teas.
One legend tells of passing soldiers using covered piles of tea leaves as mattresses, thus bruising the leaves and creating oxidation, which gives black tea its dark color. Another tale tells that while a passing army entered the Fujian province, they decided to take shelter at a nearby tea factory. This ended up delaying production at the factory, where tea leaves were left out in the sun, resulting in a longer oxidization as well as darker leaves.
Trying to speed up the drying time, they decided to smoke the leaves over pine wood, thus creating Lapsang Souchong, which became one of the very first black teas.
Both legends sound very plausible. Whichever it was, we are grateful to now be able to enjoy many varieties of delicious black teas.
Soon enough, “black teas” from the Wuyi Mountains were among the first to gain such success in Europe. Compressed post-fermented teas (pu-erh) were already known as “black teas” in China, the term was expropriated by Western traders (specifically British and Dutch) who began identifying Chinese “red teas” as “black teas” due to the color of the dark, dry leaves. Today in the Western world red teas are still being referred to as “black teas”.
Although Chinese black (red) teas are quite unlike the common ones that we now see in the West.
In China, the chilly winters let the tea plant enter a dormant period, during which carbohydrates are stored as energy reserves. During spring these natural sugars are sent to the leaves, thus creating naturally sweet flavors.
On the other hand, most “English-style” black teas are being cultivated in warmer climates like India or Africa, where quicker growth leaves the plant less time to produce its favorable complex flavors.
Note that the common Western tradition of drinking black tea with milk and sugar only came about to mask or enhance an otherwise quite unsophisticated flavor. We recommend drinking your next cup of quality black tea without either to truly get reacquainted with this complex tea.