Scattered about the centro storico (historical centre) are a number of distinctively-shaped marble tablets that sport the names of the rioni, the 14 administrative districts of the city, which were created by Pope Benedict XIV (r. 1740-58). Each tablet bears the word RIONE, a number, a name and a coat of arms.
The situation remained virtually unchanged until 1871, the year in which Rome became the capital of the Kingdom of Italy. The number of districts grew as the population increased and the city expanded. In 1921, the final rione was added, bringing the total to twenty-two.