Lübeck to the Peace of Perleberg on 23 August 1420, which stipulated that all the pawned areas, which Eric IV, Eric V and John IV had violently taken in 1401, were to be irrevocably ceded to the cities of Hamburg and Lübeck. Hamburg-Lübeck Condominium The cities transformed the acquired areas into the "Beiderstädtischer Besitz" (bi-urban condominium; cooperatively governed possession), ruled by bailiffs in four year terms, alternately staffed by one of the cities. In 1446 the bailiffs' terms were increased to six years, and in 1620 to life terms. In 1542 bailiff Ditmar Koel introduced the Protestant Reformation in the co-governed municipalities. The area was formally annexed to the First French Empire as part of Bouches de l'Elbe département between 1811 and 1813. Thereafter, the area was restored to Hamburg and Lübeck, both sovereign states. The first railway in Northern Germany was opened between Hamburg and Bergedorf by the Hamburg-Bergedorf Railway Company in 1842. In the 1860s the Condominium issued its own postage stamps. In 1863 the condominium measured 1039,99 million square Hamburg foot (1 Hamburg foot =286,57 mm), of which 947,34 million sqft were Bergedorf city and the four Vierlande municipalities (Altengamme, Curslack, Kirchwerder and Neuengamme) and 92,65 million sqft of Geesthacht (since 1937 no part of today's borough of Bergedorf anymore). Hamburg rural seigniory Effective of 1 January 1868 Lübeck sold its share in the bi-urban condominium to the Free and Hanseatic City of Hamburg for 200,000 Prussian thaler. Hamburg integrated the area into its state territory, forming there the Landherrenschaft Bergedorf (i.e. Bergedorf rural seigniory) comprising the cities of Bergedorf and Geesthacht and a number of rural municipalities not integrated into the city of Hamburg proper. By the Greater Hamburg Act of 1937 the exclave of Geesthacht was ceded to Schleswig-Holstein. Bergedorf Borough of Hamburg On 1 April 1938 Bergedorf city and the other municipalities became the Borough of Bergedorf, an integrated part of the city of Hamburg. Bergedorf is also known by its nickname Garden of Hamburg. Geography Located in the south-east of the city, the borough of Bergedorf comprises the districts of Allermöhe, Altengamme, Bergedorf, Billwerder, Curslack, Kirchwerder, Lohbrügge, Moorfleet, Neuallermöhe (new district since January 2011), Neuengamme, Ochsenwerder, Reitbrook, Spadenland and Tatenberg. In 2017 the city of Hamburg started planning the new quarter Oberbillwerder which is located in today's Billwerder. In 2006, according to the statistical office of Hamburg and Schleswig-Holstein, the borough of Bergedorf