What kind of tea from China did the Russians prefer over the past 400 years? I read this Wiki page, but the information is quite scarce. I know that tea bricks were exported through the caravan trade routes and that's about it.
A quick search yielded that the first varieties imported into Russia from China were known as "Russian Caravan" from the caravan trade routes.
It was characterized by a smoky flavor from contaminants from campfires and road debris.
Pettigrew, Jane (1999). The Tea Companion. City: Viking Australia. ISBN 0-670-88401-4.