Langenhagen is a town in the Hanover district of Lower Saxony, Germany. From 1866 to 1868, Robert Koch worked in Langenhagen. On 18 Jun…Langenhagen is a town in the Hanover district of Lower Saxony, Germany. From 1866 to 1868, Robert Koch worked in Langenhagen. On 18 June 1972, Red Army Faction terrorist Ulrike Meinhof was arrested in Langenhagen.