They raised the standard of revolt.

Igor crushed the insurrection with energy which astonished all who knew him, and which spread his fame far and wide through all the wilds of Russia, as a monarch thoroughly capable of maintaining his command.
Far away in unknown realms, beyond the eastern boundary of Russia, where the gloomy waves of the Irtish, the Tobol, the Oural and the Volga flow through vast deserts, washing the base of fir-clad mountains, and murmuring through wildernesses, the native domain of wolves and bears, there were wandering innumerable tribes, fierce, cruel and barbarous, who held the frontiers of Russia in continual terror.

They were called by the general name of Petchenegues.

Igor was compelled to be constantly on the alert to defend his vast frontier from the irruptions of these merciless savages.

This incessant warfare led to the organization of a very efficient military power, but there was no glory to be acquired in merely driving back to their dens these wild assailants.