When Italy was unified in 1861, the most important city was missing: Rome. It was the seat of the Ecclesiastical State, which in that year also included large parts of the region of Lazio. On 20 September 1870, the Italian royal army took the city in spectacular fashion (read the story here), putting an end to the Pope’s worldly power. The kingdom of Italy had achieved unification on this day. With the Vatican, the pope was given his own territory. Rome became the formally the capital of Italy in February 1871. The consequences were very far-reaching: the court and the government apparatus moved from Florence to Rome. The city’s new political status promised economic growth. This double perspective led countless job seekers to migrate to Rome. This created a sustained population growth that was measured by the Roman censuses since 1871.
The tables
The data below come from two sources. Sanfilippo in the third column stands for the historian Mario Sanfilippo, while the abbreviation ISTAT refers to the National Institute of Statistics in Rome. The table gives the Roman Censuses of Population since 1871 up to 1951. Only the Istat also gives a percentage for growth plus the date of the census.
| Jaar | Datum | Sanfilippo | ISTAT | % |
| 1871 | 31/12 | 244.844 | 209.222 | – |
| 1881 | 31/12 | 300.467 | 269.813 | 29.0 % |
| 1891 | – | 386.626 | – | – |
| 1901 | 10/02 | 462.783 | 416.028 | 52.2 % |
| 1911 | 10/06 | 542.123 | 511.076 | 22.8 % |
| 1921 | 01/12 | 691.661 | 650.258 | 27.2 % |
| 1931 | 21/04 | 1.008.083 | 916.858 | 41.0 % |
| 1941 | – | 1.403.307 | – | – |
| 1945 | – | 1.500.513 | – | – |
| 1951 | 04/11 | – | 1.626.793 | 43.6 % |
Sanfilippo mentions that the years 1881, 1941 and 1945 he gives are not based on censuses. He calculated the numbers based on data in the Municipal Archives. Compared to the Istat censuses, the numbers he provides are considerably higher. He offers no explanation for it.
The censuses from 1871 onwards were based on the concept of the family. Only in 1901 did each member of the family have to fill in their own form.
Notes on Roman Censuses since 1871
- Mario Sanfilippo, Le tre città di Roma. Lo sviluppo urbano dalle origini a oggi. Bari-Roma: Laterza, 1993.
- ISTAT = Istituto nazionale di statistica. The website is in Italian and in English.
