Versailles was made the "préfecture" of the Seine-et-Oise "département" at its inception in March 1790 (at which time Seine-et-Oise had approximately 420,000 inhabitants). By the 1960s, with the growth of the Paris suburbs, the "Seine-et-Oise" had reached more than 2 million inhabitants, and was deemed too large and ungovernable, and thus it was split into three "départements" in January 1968. Versailles was made the "préfecture" of the Yvelines "département", the largest chunk of the former "Seine-et-Oise". At the 2017 census the "Yvelines" had 1,438,266 inhabitants.