Founded in 1985, it was the very first regional office in the European Union. In 1987 the so-called information office of the Free and Hanseatic City of Hamburg became the Hanse-Office, a common institution of the Länder Hamburg and Schleswig-Holstein to the European Union. The Land Niedersachsen also participated until the opening of its own office in 1990. Since then, the Hanse-Office has successfully defended the interests of Hamburg and Schleswig-Holstein in the framework of the EU. The fruitful co-operation between Hamburg and Schleswig-Holstein is rather unique and sets an example of a lasting northern-German co-operation.