Frankfurt, formally Frankfurt am Key (German: [ˈfʁaŋkfʊʁt ʔam ˈmaɪn] (pay attention); Hessian: Frangford am Maa, lit. Frank ford on the Main), is one of the most heavily populated city in the German state of Hesse. Its 763,380 inhabitants as of 31 December 2019 make it the fifth-most heavily populated city in Germany. On the river Key (a tributary of the Rhine), it forms a continual urban sprawl with the neighboring city of Offenbach am Key and also its city area has a population of 2.3 million. The city is the heart of the larger Rhine-Main Metropolitan Area, which has a populace of 5.5 million and also is Germany's second-largest urban area after the Rhine-Ruhr Area. Frankfurt's central organization area exists about 90 km (56 mi) northwest of the geographical facility of the EU at Gadheim, Lower Franconia. Like France and Franconia, the city is named after the Franks. Frankfurt is the biggest city in the Rhine Franconian dialect area. Frankfurt was a city state, the Free Cit...