The urban agglomeration of Longueuil was created on January 1, 2006 as a result of the de-amalgamation process brought upon by the Charest government. It encompasses all the boroughs that were merged into the previous city of Longueuil and still retains the same area as that mega-city. The urban agglomeration of Longueuil is coextensive with the territory equivalent to a regional county municipality (TE) and census division (CD) of Longueuil, whose geographical code is 58.