This tea is also known as Imperial Russian. A traditional blend that was exported to the Russian Royal family on the 'camel train' from China.
It is a blend of Keemun and Oolong teas, although originally it would have contained a small amount of Lapsang Souchong.
The 4000 mile long Silk Route would have meant the tea taking over six months to move from China through to the main Russian cities, and it is said that the tea took on the smoky flavour due to all the camp fires that would have occurred during this journey, but as the Chinese used quite specific methods of smoking their tea I would be surprised if this was the case.
Imperial Russian can also be flavoured with bergamot or other citrus scents, and a slice of orange or lemon could be a refreshing addition.
I use boiling, 100oC water and infuse for between four minutes and I make a second infusion that I brew for five minutes.