Keemun (qímén, or qi2men2, in Pinyin Chinese) is a light Chinese black tea with a smooth, well-balanced taste. It doesn't have such rich floral overtones as Darjeeling, and it's a little stronger, but along with Ceylon it occupies a similar niche: black teas with sufficiently smooth, gentle flavours that they really don't need milk or sugar, but with enough body to take them if you're that way inclined. It doesn't carry the caffeine kick of a tea like Assam, but it's one of the strongest teas that are good without milk - it out-caffeines oolong and green tea by a long way. It has a pleasant, mellow, very teasome aroma with just a hint of floweriness.
Keemun is grown in Qimen County in Anhui province of China, which is where it gets its name; it was first produced in 1875 after a former civil servant by the name of Yu Quianchen travelled to the Fujian province to learn about how to make black tea. When he returned to Anhui - already well-known for green teas including gunpowder tea and the pointy-leafed Tai Ping Monkey King, among others - he found that he could produce black tea of exceptional quality from the same leaves used to make green tea. Keemun black tea was a hit, making its way into many English Breakfast blends along with Assam and Ceylon and growing in popularity until it surpassed even Darjeeling to become the most popular black tea in the world.
Many different grades of Keemun exist. Some come as long, slightly twisted leaves, like the Mao Feng and Xin Ya varieties; others, like Hao Ya and the other gongfu grades, are smaller and more tightly rolled. Hao Ya is renowned among Keemuns; it is extremely tippy, with a fruity taste and a unique aroma. The delicate flavours of the finest Keemuns should really be enjoyed without milk, but less special Keemuns take it well.