The "Métropole du Grand Paris" was defined by the law of 27 January 2014 on the modernization of public territorial action and affirmation of cities as part of Act III of decentralization.

The plan was first announced on 17 September 2007 during the inauguration of "La Cité de l'architecture et du patrimoine", when Sarkozy declared his intent to create a "new comprehensive development project for Greater Paris".

[4] The architects leading the ten multi-disciplinary teams were: Jean Nouvel, Christian de Portzamparc, Antoine Grumbach, Roland Castro, Yves Lion, Djamel Klouche, Richard Rogers, Bernardo Secchi, Paola Viganò, Finn Geipel, Giulia Andi, and Winy Maas.

[7] The original plan for the Métropole declared these objectives: "The Métropole of Grand Paris is established in order to define and implement metropolitan action to improve the quality of life of its residents, reduce inequalities between regions within it, to develop an urban, social and economic sustainability model, tools to improve attractiveness and competitiveness for the benefit of the entire national territory.

"[9] Independently to the process described above, a position of Minister for Le Grand Paris was created and Christian Blanc was appointed to occupy it.

The transport plan will be carried out in ten years, at a cost of 35 billion euros funded by the state, local governments and new debt.

The 131 communes of the Métropole du Grand Paris are grouped in 12 établissements publics territoriaux (EPT) or territoires, which replaced the existing inter-communal public institutions and inherited their competences such as sport and socio-cultural amenities, water supply, sanitation, waste management and some urban and social policies.