Quote Originally Posted by Theodoret
Cegorach1 mentions Poland-Lithuania. This site gives a lot of good information on them. Both the Polish/Lithuanian armies and those of their intermittant enemies the Tartars of the Crimea and the Cossacks were very cavalry heavy. Interestingly there is mention of Tartar allies giving the Swedes a bit of trouble in one of the campaigns towards the end of the 17th century. Rather strange to have a modern (for the time) European army being taken apart by something as archaic as a horde of horse-archers.



The Cossacks were not very good cavalrymen at that time, the Tatars were.

And the Tatars shouldn't be underestimated, even when their forces were pretty small - no hordes.
These guys were the best cavalrymen at that time and the most agile.
The Swedes were really scared because of them.