The Jade Treaty of 20 July 1853 between Kingdom of Prussia and Grand Duchy of Oldenburg provided for the handover of 340 hectares of Oldenburg territory at what is now Wilhelmshaven

Wilhelmshaven

Wilhelmshaven is a coastal town in Lower Saxony, Germany. It is situated on the western side of the Jade Bight, a bay of the North Sea.-History:...

, Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, on the western shore of the Jade Bight east of Bremerhaven

Bremerhaven

Bremerhaven is a city at the seaport of the free city-state of Bremen, a state of the Federal Republic of Germany. It forms an enclave in the state of Lower Saxony and is located at the mouth of the River Weser on its eastern bank, opposite the town of Nordenham...

. It was considered the best natural deep-water port in the German North Sea coast, and a good place for the naval base Prussia wished to build. The navy base built there became the nucleus of today's Wilhelmshaven.

Since before 1848 Prince Adalbert of Prussia

Adalbert of Prussia

Prince Adalbert of Prussia was a son of Prince Wilhelm of Prussia and Landgravine Marie Anna of Hesse-Homburg. He was a naval theorist and admiral. He was instrumental during the Revolutions of 1848 in founding the first unified German fleet, the Reichsflotte...

 had worked to build a Prussian navy. During the First Schleswig War of 1848-51, Prussia had virtually no navy. Within a few days the Danish navy had destroyed German maritime commerce in the North Sea

North Sea

In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

 and the Baltic Sea

Baltic Sea

The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

. By 1852 Prussia had started to expand its fleet and needed a good port on the North Sea, something they had not had since the Congress of Vienna

Congress of Vienna

The Congress of Vienna was a conference of ambassadors of European states chaired by Klemens Wenzel von Metternich, and held in Vienna from September, 1814 to June, 1815. The objective of the Congress was to settle the many issues arising from the French Revolutionary Wars, the Napoleonic Wars,...

. The Jade Bay area offered deep water, a good anchorage and no ice in winter.. Oldenburg welcomed the idea of Prussia as a powerful ally. Also, they needed money to end the Bentinckschen succession dispute. From 1854 onward Prussia established the fortress, naval base and city of Wilhelmshaven, which would be useful in the Second Schleswig War of 1864.