The commune of Dakar has been in continuous existence since 1887, being preserved by the new state of Senegal after independence in 1960, although its limits have varied considerably over time. The limits of the commune of Dakar have been unchanged since 1983. The commune of Dakar is ruled by a democratically elected municipal council (''conseil municipal'') serving five years, and a mayor elected by the municipal council. There have been 20 mayors in Dakar since 1887. The first black mayor was Blaise Diagne, mayor of Dakar from 1924 to 1934. The longest-serving mayor was Mamadou Diop, mayor for 18 years between 1984 and 2002.