A new subdivision of the city under Napoleon was ephemeral, and there were no serious changes in the organisation of the city until 1870 when Rome became the third capital of Italy. The needs of the new capital led to an explosion both in the urbanisation and in the population within and outside the Aurelian walls. In 1874, a fifteenth rione, Esquilino, was created on the newly urbanised zone of Monti. At the beginning of the 20th century other rioni were created (the last one was Prati – the only one outside the Walls of Pope Urban VIII – in 1921). Afterwards, for the new administrative subdivisions of the city, the term "quartiere" was used. Today all the rioni are part of the first Municipio, which therefore coincides completely with the ''historical city'' (''Centro Storico'').