The agglomeration has grown well beyond the city's administrative limits. The

Religion[edit]

According to a 2011 survey by IFOP, a French public opinion research organisation, 47 percent of residents of the Paris Region (Île-de-France) identified themselves as Roman Catholic, though just 15 percent said they were practising Catholics, while 46 percent were non-practicing. In the same survey, 7 percent of residents identified themselves as Muslims, 4 percent as Protestants, two percent as Jewish, and 25 percent as without religion.^[148]
According to INSEE, the French government statistical office, between 4 and 5 million French residents were born or had at least one parent born in a predominately Muslim country, particularly Algeria, Morocco, and Tunisia. An IFOP survey in 2008 reported that, of immigrants from these predominantly Muslim countries, 25 percent went to the mosque regularly; 41 percent practised the religion, and 34 percent were believers but did not practice the religion.^[149][150]
In 2012, Dalil Boubakeur, the Rector of the Grand Mosque of Paris and former President of the French Council of the Muslim Faith, estimated that there were 500,000 Muslims in the city of Paris, 1.5 million Muslims in the Île-de-France region, and 4 to 5 million Muslims in France.^[151]
The Jewish population of the Paris Region was estimated in 2014 to be 282,000, the largest concentration of Jews in the world outside of Israel and the United States.^[152]