New theories (I am going to be lynched for this) say that Russians were Mongols

Golden Horde was the military alliance between first Russian Czars (that came into existance long before the fall of Constantinople), Cossacks (yes, who existed way before 15th-16th centuries) and scores of non-Russians west of Volga. The purpose of this alliance was to destroy the feudal power of princes, much like French Kings used Scottish and Swiss mercinaries to break the power of nobility.
These theories do answer some interesting questions, one being: how did nomads, used to operating in steppes, managed to defeat Russians in the heart of their domain (which accidentally happen to be very very woody).
The answers are:
1. There weren't that many of them (100,000-500,000 horsemen) could not feed themselves and their horses in the mid-winter in woods. So, the Mongol army probably amounted to about 30,000.
2. They were familiar to Russian way of fighting during winter, using frozen rivers as roads.
3. Their rulers supported Orthodoxy, which in turn supported them. This explains unexplainbale before attempts to stop Mongols by venturing out of the city with priests ahead of the procession, who carried crosses to stop the invaders. If the invaders were savage nomads, no sane Russian would venture out of the city without the support of the army.
4. In short, the struggle between Mongols and Russians was the struggle between Russian autocrats and Russian nobles. After subjugating Russian princes "Mongols" sent a contingent of their troops to aid Nevsky in defeating Livonian Order and proceeded to cement the borders of the newly born Russia in the west.
That's, of course, is just a theory. Enjoy. Btw, the name Mongols, the theory claims, derives from a Greek word "megalion" - "great".
Russians were divided in Great Russians, White Russians and Small Russians.
In conclusion, all we know about Mongols comes from the studies of Western historians started in 19th century and lies spread by Romanov historians, who wanted to confirm the legitimacy and make their predecessors look like weaklings and savages.
The author of the new theory is Fomenko, his supporters are growing in numbers. Myself, I wasn't entirely convinced, but his books surely point at many inconsistences in history as we know it. Let's just say I've read enough to doubt everything I read in my history books. Until you read the original texts (which could be propaganda just like today) you cannot trust a historian who interpreted them. He could be on a payroll of some country or be hiding some facts that will ruin his own reputation.