Batu's campaign of 1237–1241 destroyed the political order of the Rus lands. Ryazan fell in December 1237, Vladimir in February 1238, and Kyiv in December 1240 after a short siege; the chronicles record the storming and burning of dozens of towns. John of Plano Carpini, passing through in 1246, described bones and skulls lying in the fields and reported that Kyiv had been reduced to some two hundred houses whose inhabitants lived in servitude. Archaeology corroborates destruction layers and mass graves at several sites, and a marked decline in urban crafts. The princes who survived became tributaries of the Golden Horde, travelling to Sarai for patents to rule and collecting tribute for the khan. No population or casualty figures exist: the chronicles record which towns were taken and burned, not how many died, and Carpini's observations are impressionistic. Modern Russian, Ukrainian and Mongolist historiographies differ sharply over how devastating and how lasting the effects were.
Batu's Mongol army destroyed the Rus principalities city by city, sacked Kyiv in December 1240, and imposed tributary rule through the Golden Horde
There is no census. Estimates rest on archaeological survey of towns and settlement density and on later fiscal records: George Vernadsky put the Rus lands at about 7.5 million before the invasion, Soviet demographers such as Urlanis nearer 5 million, so a range of 5-8 million is the usual scholarly span. Excavations at Kyiv, Ryazan and Vladimir show destruction layers and mass graves consistent with the chronicles' account of city-by-city sacking.
No defensible figures. The Rus chronicles record the destruction of named towns without counting the dead; Carpini's account of bones in the fields is descriptive; excavated mass graves establish that killing was extensive at particular sites but support no aggregate.
The storming and burning of towns, the killing of their inhabitants and the deportation of craftsmen are documented in the Rus chronicles, in John of Plano Carpini's eyewitness report and in excavated destruction layers and mass graves.
Ukraine, Russia