Why were eastern European states larger than western European states for much of history?

Upvote:2

Your generalizations about both Western and Eastern Europe are completely unfounded. For example:

The Polish-Lithuanian Commonwealth was no more centralized than the Holy Roman Empire, and perhaps even less so: the H.R.E. morphed into a Prussian led German State shortly after Poland disappeared completely.
Large swaths of France were under English (and Burgundian) suzerainty for much of the 4 centuries from 1066 to 1453.
Spain underwent a 7 1/2 century long civil war known as Reconquista from the Battle of Tours (732) until the fall of Granada (1492).
First Muslim and then Norman invaders controlled most of Southern Italy for centuries.
The Baltic states were a hodgepodge of semi-sovereign duchies when they weren't (nominally) subordinate.
The Ottomans controlled most of the Balkans, most of the time, from shortly after the Fourth Crusade until well into the 19th century.
England twice, during The Anarchy and again during Wars of the Roses, was a completely decentralized state.

That's just a partial list of exceptions, that far outnumbers your examples.

Pieter Geerkens 71937

Source: stackoverflow.com