[4] The region is made up of eight administrative departments: Paris, Essonne, Hauts-de-Seine, Seine-Saint-Denis, Seine-et-Marne, Val-de-Marne, Val-d'Oise and Yvelines.

In 1976, when its status was aligned with the French administrative regions created in 1972, it was renamed after the historic province of Île-de-France.

The region has witnessed increasing income inequality in recent decades, and rising housing prices have pushed the less affluent outside Paris.

[12] The Parisii traded with many river towns (some as far away as the Iberian Peninsula) and minted their own coins for that purpose.

[15] Christianity was introduced in the middle of the 3rd century AD by Saint Denis, the first Bishop of Paris.

The place that he finally fell and was buried became an important religious shrine, the Basilica of Saint-Denis.

As the Frankish domination of Gaul began, there was a gradual immigration by the Franks to Paris and the Parisian Francien dialects were born.

Under the rule of the Capetian kings, Paris gradually became the largest and most prosperous city in France.

Île-de-France became the term used for the territory of Paris and the surrounding province, which was administered directly by the King.

On 6 May 1976, as part of the process of regionalisation, the district was reconstituted with increased administrative and political powers and renamed the Île-de-France region.

The former department of Seine, abolished in 1968, included the city proper and parts of the petite couronne.

Politically, the region is divided into 8 departments, 25 arrondissements, 155 cantons and 1,276 communes, out of the total of 35,416 in metropolitan France.

They also create many lakes and ponds, some of which have been transformed into recreation areas, including Moisson-Mousseaux, Cergy-Neuville and Villeneuve-Saint-Georges.

The region also hosts the headquarters of the top French telecom companies and utilities, including Orange S.A., Veolia and EDF.

[21] Other major sectors of the regional economy include energy companies (Orano, Engie, Électricité de France and Total S.A.).

The two major French automobile manufacturers, Renault, in Flins-sur-Seine, and Groupe PSA, in Poissy, do much of their assembly work outside France but still have research centre and large plants in the region.

The leading French and European aerospace and defense companies, including Airbus, Thales Group, Dassault Aviation, Safran Aircraft Engines, the European Space Agency, Alcatel-Lucent, and Arianespace, have a large presence in the region.

The nuclear power industry, with its major firm being Orano, has its headquarters in Île-de-France, as does the main French oil company Total S.A., the top French company in the Fortune Global 500, and the main electric utility, Électricité de France.

[22] The largest non-government employers in the region as of the end of 2015 were the airline Air France (40,657); the SNCF (French Railways, 31,955); the telecom firm Orange S.A. (31,497); the bank Société Générale (27,361); the automotive firm Groupe PSA (19,648); EDF (Electricité de France, 18,199); and Renault (18,136).

[26] [27][28] The top tourist attraction in the region in 2017 was Disneyland Paris, which received 14.8 million visitors in 2017, followed by the Cathedral of Notre-Dame (est.

The population of immigrants is more widely distributed throughout the region than it was in the early 2000s, but the concentrations remain high in certain areas, particularly Paris and the department of Seine-Saint-Denis.

The most populated towns of the Petite Couronne are Boulogne-Billancourt, Montreuil, Saint-Denis, Nanterre and Créteil.