Rhône (French pronunciation: [ʁon]; Arpitan: Rôno) is a French department located in the central Eastern region of Auvergne-Rhône-Alpes. It is named after the river Rhône.

The Rhône department was created on August 12, 1793 when the former département of Rhône-et-Loire was split into two departments: Rhône and Loire.

Originally, the eastern border of Rhône was the city of Lyon itself, so that the communes immediately east of Lyon belonged to neighboring department. With the growth of Lyon and the spilling of the urban area into the suburban communes of Lyon, such as Villeurbanne, the limits of the department were judged impractical as they left the suburbs of Lyon outside of Rhône. Thus, Rhône was enlarged several times to incorporate into it the suburbs of Lyon from neighboring department:

With these enlargements, the area of the Rhône department increased from 2,791 km² to the current 3,249 km² (16.4% larger). At the 1999 French census, the original Rhône department would have had only 1,071,288 inhabitants, which means that the population in the territories added in the last two centuries was 507,581 inhabitants in 1999.

In 2015 the Metropolis of Lyon was separated from the Rhône department. Lyon, although no longer part of the department, remains its administrative center.

Rivers include the Rhône and the Saône (which joins the Rhône in Lyon). The neighboring departments are Ain, Isère, Loire and Saône-et-Loire.

...
Wikipedia