The Prussian state has lost about one third of its area under the Treaties of Tilsit in 1807, including the areas gained from the second and third Partitions of Poland, which now fall to the Duchy of Warsaw.

Beyond that, the king is obliged to pay a large indemnity, to cap his army at forty-two thousand men, and to allow French troops to be garrisoned throughout Prussia, effectively making the Kingdom a French satellite.

In response to this defeat, reformers such as Heinrich Friedrich Karl vom und zum Stein and Karl August von Hardenberg set about modernizing the Prussian state.

Among their reforms are the liberation of peasants from serfdom, the Emancipation of Jews, and making full citizens of both groups.