Colonna, City of Rome  Colonna is the 3rd "rione" of Rome, identified by the initials R. III and located at the city's historic center in Municipio I. It takes its name from the Column of Marcus Aurelius in the Piazza Colonna, the rione's main piazza. The rione's coat of arms is a now a silver column, representing the Column of Marcus Aurelius, on a red background. However, the insignia originally consisted of three azure bands against a silver background. The area of the "rione" is split up in two parts, divided by Via del Corso, a western flat part and an eastern hilly part, that reaches to one side of the Pincian Hill. During the short-lived Roman Republic of 1798 it also included the hill itself and was called Pincio rather than Colonna. In the ancient Rome, in the hilly part the most rich patricians had their sumptuous "domus", while the flat region used to belong to the "Campus Martius" and was studded with monuments: in addition to the Column of Marcus Aurelius, from which the "rione" takes its name, also the Temple of Hadrian and the Solarium Augusti were located in the area. In the 16th century the "rione" experienced a remarkable development, as Pope Alexander VII refurbished Piazza Colonna and his family bought from the Aldobrandini family the palace that overlooked it. The relevance of Colonna increased further in 1696, after the Palazzo Montecitorio was chosen as the headquarter of the pontifical police and as the seat of the papal courthouse and of the customs house. Following the unification of Italy and the proclamation of Rome as the capital of the new State, the northwestern part of the "rione" - hilly and packed with villas and parks - experienced a real "construction fever" as a huge number of new buildings were constructed to satisfy the demands related to the new role of the city. Eventually, in 1921 this area was detached from Colonna to constitute a new "rione", Ludovisi. Today the rione covers 0.2689 km2 and as of 2011 had 2547 inhabitants. The "rione" borders to the north with Campo Marzio (R. IV), from which is separated by Via di Campo Marzio, Piazza di San Lorenzo in Lucina, Via Frattina, Via dei Due Macelli, Via Capo le Case and Via Francesco Crispi; and with Ludovisi (R. XVI), with Via degli Artisti, Via di Sant'Isidoro and Via Vittorio Veneto marking the boundary.