1528 census of the Grand Duchy of Lithuania

The Muscovite–Lithuanian Wars brought first substantial territorial losses and caused a fundamental shift in the military. Instead of being a privilege that brought profit from war loot and career opportunities in newly acquired territories, military service became an expensive duty in defense of the motherland.[2] Each soldier had to provide his own weapons, armor, horse, and food. The nobles made their living off agriculture and looked for ways to shirk their army responsibilities.[2] The state needed ways to enforce the conscription and started keeping detailed lists and inventories of who reported for duty and who did not. These inventories were made at the time and location of army gathering. In 1528, scribes visited nobles and their properties to count and verify the number of peasant households.[2] The First Statute of Lithuania codified the procedures of reporting for military duty.[2]

The census determined the maximum size of the army. Nobles could provide about 20,000 cavalrymen, magnates and city dwellers could provide additional 10,000.[1] Because the census counted only households, it is difficult to extrapolate the number of residents. German Werner Conze estimated 1.3 million residents. Henryk Łowmiański and Jerzy Ochmański pointed out that Conze did not account for Grand Duke's and church lands that were not counted in the census and increased the estimate to more than 2 million residents.[3]