<P> The departments were created in 1790 as a rational replacement of Ancien Régime provinces with a view to strengthen national unity; the title "department" is used to mean a part of a larger whole . Almost all of them were named after physical geographical features (rivers, mountains, or coasts), rather than after historical or cultural territories which could have their own loyalties . The division of France into departments was a project particularly identified with the French revolutionary leader the Abbé Sieyès, although it had already been frequently discussed and written about by many politicians and thinkers . The earliest known suggestion of it is from 1764 in the writings of d'Argenson . They have inspired similar divisions in many countries, some of them former French colonies . </P> <P> Most French departments are assigned a two - digit number, the "Official Geographical Code", allocated by the Institut national de la statistique et des études économiques . Overseas departments have a three - digit number . The number is used, for example, in the postal code, and was until recently used for all vehicle registration plates . While it is common for residents to use the numbers to refer to their own department or a neighbouring one, more distant departments are generally referred to by their names, as few people know the numbers of all the departments . For example, inhabitants of Loiret might refer to their department as "the 45". </P> <P> In 2014, President François Hollande proposed to abolish departmental councils by 2020, which would have maintained the departments as administrative divisions, and to transfer their powers to other levels of governance . This reform project has since been abandoned . </P> <P> The first French territorial departments were proposed in 1665 by Marc - René d'Argenson to serve as administrative areas purely for the Ponts et Chaussées (Bridges and Highways) infrastructure administration . </P>

France is an example of a homogeneous region