The War of the Third Coalition lasted from about 1803 to 1806. Following defeat at the Battle of Battle of Austerlitz by the French under Napoleon in December 1805, Holy Roman Emperor Francis II abdicated, and the Empire was dissolved on 6 August 1806. The resulting Treaty of Treaty of Pressburg established the Confederation of the Rhine in July 1806, joining together sixteen of France's allies among the German states (including Bavaria and Württemberg). After the Battle of Battle of Jena–Auerstedt of October 1806 in the War of the Fourth Coalition, various other German states, including Saxony and Westphalia, also joined the Confederation. Only Austria, Prussia, Danish Holstein, Swedish Pomerania, and the French-occupied Principality of Erfurt stayed outside the Confederation of the Rhine. The War of the Sixth Coalition from 1812 to winter 1814 saw the defeat of Napoleon and the liberation of Germany. In June 1814, the famous German patriot Heinrich vom Stein created the Central Managing Authority for Germany (Zentralverwaltungsbehörde) in Frankfurt to replace the defunct Confederation of the Rhine. However, plenipotentiaries gathered at the Congress of Vienna were determined to create a weaker union of German states than envisaged by Stein.
The German Confederation was created by the 9th Act of the Congress of Vienna on 8 June 1815 after being alluded to in Article 6 of the 1814 Treaty of Paris, ending the War of the Sixth Coalition.
The Confederation was formally created by a second treaty, the Final Act of the Ministerial Conference to Complete and Consolidate the Organization of the German Confederation. This treaty was not concluded and signed by the parties until 15 May 1820. States joined the German Confederation by becoming parties to the second treaty. The states designated for inclusion in the Confederation were:
- Anhalt-Bernburg (inherited by the Duke of Anhalt-Dessau, 1863)
- Anhalt-Köthen (inherited by the Duke of Anhalt-Dessau, 1847/53)
- Austrian Empire (including Crown of Bohemia – Bohemia, Moravia and Austrian Silesia – and Austrian lands – Austria, Carinthia, Carniola, the Littoral, Salzburg, Styria, Tyrol, and Vorarlberg)
- Electorate of Hesse (also known as Hesse-Kassel)
- Grand Duchy of Hesse (also known as Hesse-Darmstadt)
- Hohenzollern-Hechingen (became part of Prussia in 1850)
- Hohenzollern-Sigmaringen (became part of Prussia in 1850)
- Holstein and Lauenburg, held by Denmark
- Luxembourg, held by the Netherlands
- Reuss, elder line
- Reuss, younger line
- Saxe-Coburg (ruler became Duke of Saxe-Coburg and Gotha 1826)
- Saxe-Gotha (partitioned 1826)
- Saxe-Hildburghausen (ruler became Duke of Saxe-Altenburg, 1826)
- Hesse-Homburg (inherited by the grand-duke of Hesse-Darmstadt, 1866) (joined by treaty in 1820)
- Lübeck (joined by treaty in 1820)
- Frankfurt (joined by treaty in 1820)
- Bremen (joined by treaty in 1820)
- Hamburg (joined by treaty in 1820)
In 1839, as compensation for the loss of the province of province of Luxemburg to Belgium, the Duchy of Limburg (held by the Netherlands) was created and it was a member of the German Confederation until its dissolution in 1866. The cities of Maastricht and Venlo were not included in the Confederation.
The monarchs of the member states of the German Confederation meet at Frankfurt in 1863
The Austrian Empire and the Kingdom of Prussia were the largest and by far the most powerful members of the Confederation. Large parts of both countries were not included in the Confederation, because they had not been part of the former Holy Roman Empire, nor had the greater parts of their armed forces been incorporated in the federal army. Austria and Prussia each had one vote in the Federal Assembly.
Six other major states had one vote each in the Federal Assembly: the Kingdom of Bavaria, the Kingdom of Saxony, the Kingdom of Kingdom of Württemberg, the Electorate of Hesse, the Grand Duchy of Baden, and the Grand Duchy of Hesse.
Three member states were ruled by foreign monarchs: the King of Denmark as Duke of Holstein; the King of the Netherlands as Grand Duke of Luxembourg and Duke of Limburg; and the King of Great Britain (until 1837) as King of Hanover were members of the German Confederation. Each of them had a vote in the Federal Assembly.
The four free cities of Bremen, Frankfurt, Hamburg, and Lübeck shared one vote in the Federal Assembly.
The 23 remaining states shared five votes in the Federal Assembly.