This map shows the expansion of Prussia between the Treaty of Tilsit in 1807 and the proclamation of the German empire in 1871. By the Treaty of Tilsit, which followed the Prussian defeat in the battle of Jena in 1807 against Napoleon I, the Prussian King Frederick William III ceded all possessions west of the Elbe River, as well as significant areas that had been gained by the first, second and third partitions of Poland. The Prussian monarchy was reduced to Brandenburg, Silesia, the Pomeranian provinces, parts of West Prussia without Danzig (Gdańsk), and East Prussia. Prussia also had to reduce its military, accept French occupation of much of its territory, and pay significant indemnities to Napoleon Bonaparte.  

Following the period of French domination over Europe, the French army was defeated by two armies of the Seventh Coalition at the Battle of Waterloo on June 18, 1815, which marked the end of the Napoleonic Wars. After the downfall of the French Emperor, the participants of the Congress of Vienna (1814-1815) agreed upon a peace plan and possible restructuring of the European political and constitutional order.

Based on the final article, Prussia gained control of significant territories indicated on the map. This included the duchies of Cleves, Berg, Gelderland, and Jülich, the ecclesiastical principalities of Trier and Cologne, the free cities of Aachen and Cologne, nearly one hundred small lordships and abbeys, which would all be amalgamated into the new Prussian Rhine Province, as well as the province of Westphalia.

The Grand Duchy of Posen, created from territories annexed by Prussia after the Partitions of Poland, was formally established following the Napoleonic Wars in 1815. Prussia also gained Swedish Pomerania in exchange for Saxe Lauenburg, which became Danish. The Congress of Vienna also awarded the greater part of Saxony to Prussia.

The Austro-Prussian War of 1866 led to further territorial gains for Prussia and Prussian dominance over the German states. As a result of the war, the new province of Hesse-Nassau was created, which included Nassau, Hesse-Kassel, Hesse-Darmstadt and Frankfurt. Schleswig and Holstein became the Province of Schleswig-Holstein. Hanover became the Province of Hanover. Thus, Prussia established its hegemony and Austria lost all official influence over member states of the former German Confederation.

Finally, the Franco-Prussian War of 1870-1 had a lasting impact on Europe. The war led to additional territorial gains for Prussia, hastened German unification, and altered the balance of power on the continent, with the new German state replacing France as the dominant European land power.

As a result of the war, Germany annexed Alsace-Lorraine in 1871, and several states joined the German empire, including Hesse, the Grand Duchy of Mecklenburg-Schwerin, the Kingdom of Württemberg, the Kingdom of Saxony, the Grand Duchy of Baden, the Kingdom of Bavaria, Hamburg, the Grand Duchy of Oldenburg, and the Thuringian duchies.