Wikipedia
Essonne
Essonne is a French department in the region of Île-de-France. It is named after the Essonne River.
It was formed on 1 January 1968 when Seine-et-Oise was split into smaller departments.
Essonne (river)
The Essonne is a long French river. It is a tributary off the left bank of the Seine. Its course crosses the departments of Loiret and Essonne, and it gives its name to the latter. The Essone's name and the present name of its higher course (the Œuf) originate in Acionna, a Gallo-Roman river goddess attested at Orléans (Genabum).