The name of the district means "column", referring to the column of Marcus Aurelius (c.180 AD), now standing in piazza Colonna.
The medieval name Regio Columne et Sancte Marie in Aquiro, mentioned the aforesaid column and the church of Santa Maria in Aquiro, founded probably around year 400, whose name is of uncertain etymology (its early form was in Cyro). The church is still standing, though it's shape was altered and enlarged in the 16th century.

piazza Colonna, with the column of Marcus Aurelius and (right) Palazzo Chigi

In some versions it features three bands variously oriented over a white background.
More often, the bands are replaced by a column, whose shaft in a spiral pattern clearly refers to the monument dedicated to Marcus Aurelius.

Piazza Mignanelli; via Frattina; piazza San Lorenzo in Lucina; via di Campo Marzio; via della Maddalena; via del Pantheon; piazza della Rotonda; via del Seminario; piazza Sant'Ignazio; via del Caravita; via del Corso; via delle Muratte; via di Santa Maria in Via; piazza San Claudio; via del Pozzetto; via del Bufalo; via del Nazareno; via del Tritone; piazza Barberini; via Veneto; via Sant'Isidoro; via degli Artisti; via Francesco Crispi; via Capo le Case; via dei Due Macelli.

(the black numbers in square brackets refer to the map below)

a detail of the column's reliefs
The shape of Colonna recalls that of a jigsaw puzzle piece that fits among several neighbour districts: on its western side it covers a part of the ancient Campus Martius plains, while on the other side it thrusts between the present Campo Marzio (IV) and Trevi (II) districts, reaching with its eastern tip one side of the Pincio Hill, where the streets grow rather steep.
Colonna was never densely populated before the late 16th century, when wealthy and aristocratic families had a considerable number of palazzi built for themselves, especially along via Lata, i.e. the present via del Corso.

painted house in via Sistina (1890)

The two halves of the district join not far from piazza Colonna [1], the spot where the famous commemorative monument of emperor Marcus Aurelius stands. It is quite similar in shape to the column built for Trajan about 70 years before, with scenes in high relief that wind all the way up to the top, depicting the emperor's victorious military feats against the Quadi, Marcomanni and Sarmatian tribes (inhabitants of the lands from the present central Germany to Ukraine), in two campaigns fought between AD 171 and 175. The column consists of 28 cylindres of marble, slightly less than 4 m (13 ft) in diameter, with a central staircase, lit by thin windows opened along the shaft.
On the top of the columns once stood a bronze statue of Marcus Aurelius, that went lost in time; in the late 1500s pope Sixtus V had it replaced with a similar one of St.Paul (left). On the same occasion, the monument was also stood on a new taller base, with an inscription that wrongly refers the column to Antonine the Pious, the father of Marcus Aurelius (whence the common but incorrect alternative name Antonine column).
the column iin 1575, without the statue and with the original base;
on the nearby hill, still bare, now stands Palazzo di Montecitorio
Looking carefully at the central part of the shaft, a few elements appear slightly shifted off-axis: during the Middle Ages, some strong earthquakes rocked the monument, causing the cylinders to move, although the column is still perfectly steady. Below the column is a beautiful late 16th century fountain shaped as a tub, by Giacomo Della Porta (see Fountains).
After his death, also Marcus Aurelius was worshipped as a god, as almost every late emperor; a temple dedicated to him was built on the western side of the square, where now stands the large building with a porch, of the first half of the 1800s, named after banker Wedekind, also known as Il Tempo building, being the seat of the Roman daily paper Il Tempo since 1945.

The other large building that faces the square is the fine Palazzo Chigi. Its making started around 1570, for the Aldobrandini family, who in 1596 also had a small church built, adjoining their mansion, dedicated to St.Paul. But the latter was soon taken down, in c.1620, in order to enlarge the building, which over the years underwent several further refurbishments. In 1916 it acquired its present shape, and it was chosen as the seat of the Ministry of Foreign Affairs. Since 1959, instead, it hosts the Cabinet of Ministers. It still bears the name of the Chigi family of rich bankers, who had purchased it in 1659.

On the opposite side of via del Corso stretches the front of the Galleria Alberto Sordi (formerly Galleria Colonna), the most elegant among Rome's arcades, described in the relevant page.

In a square adjacent to piazza Colonna stands the massive Palazzo di Montecitorio [2], the seat of the Lower Chamber of the Italian Parliament. Its name probably comes from the Latin Mons Acceptorius or Mons Citatorius, a small artificial embankment created by pre-Roman dwellers in order to reclaim what once was a swamp, and build dry huts on less wet soil. During the centuries, its original height flattened down, although the pavement leading to the Parliament's building is still clearly sloping.
Palazzo di Montecitorio was drawn by Gianlorenzo Bernini around 1650, but its making was only completed half a century later. The Pamphilj family, relatives to the pope who had commissioned the work (Innocent X), were to become the owners, but in the end its purpose was completely changed, becoming Rome's main law court.

la facciata di Palazzo di Montecitorio

Only after the fall of the Papal State, in 1870, it was chosen as the seat of the Lower House of the newborn Italian parliament; but since its halls became very soon inadequate to the growing number of deputies, the depth of the building was doubled. Now its back, built in travertine and red bricks, with towers in the corners, makes a strong contrast with the design of the late Baroque front.

Before the building stands the obelisk of Psamtik II (see the Obelisks monograph for details).

Not far, in piazza di Pietra [3], one side of a late 17th century building, which used to house the land customs' offices, is completely covered by the impressive remains of the Temple of Hadrian (c.AD 145). These eleven columns are the only part of the ancient Roman structure now left standing, but thanks to the brilliant solution of enclosing them within the more steady building, they look much better than simple 'fragments'.
On the left of the temple, a narrow winding lane leads to piazza di Sant'Ignazio, a charming square famous for its peculiar elliptical shape, where the church of Sant'Ignazio stands, just beyond the boundary with Pigna district.

i burr˛ in piazza Sant'Ignazio
The Rococo style buildings opposite the church [4] were called burr˛, a local corruption of the word bureau, as during Rome's French occupation they housed some government offices (i.e. bureau in French), and also because the shape of the buildings resembles a chest of drawers (also called a bureau). The name burr˛ was then given also to the lane that windingly runs all around the buildings.
resti del Tempio di Adriano

In the corner of the district pointing towards the Pantheon, where Colonna borders Sant'Eustachio and Pigna districts, a plaque dated 1906 remembers that in those years piazza della Rotonda was paved for some time with a real parquet, thanks to the timber given to Rome from the Municipality of Buenos Aires, the Argentinian capital where since the late 19th century many Italians had emigrated, so the noise made by the carriage traffic would not disturb the tombs of the first two kings of Italy. However, that type of paving proved soon inadequate, and was taken away.

the plaque that remembers the gift →
Nearby, a tiny square is overlooked by the narrow, yellowish fašade of Santa Maria Maddalena's church [5], more commonly known as la Maddalena. It was founded in the late 1500s, over the site of a preexisting chapel of the 14th century, and it took over one and a half centuries to be completed (1735), as testified by the front, which boasts a flamboyant Rococo style.
The history of this church is linked to the life of Camillo de' Lellis (1550-1614), a mercenary captain who, after being healed from a wound, decided to give up weapons and dedicate his life to the sick. He became a man of religion, and for the rest of his life worked in the hospital which once stood by Santa Maria Maddalena's church, where later he was also buried. He was proclaimed a saint shortly after the building was finished; up to the late 1800s, on the day of his death (July 14), the faithful were given a special healing potion, obtained by mixing water with a little dust coming from the saint's tomb.

← Santa Maria Maddalena

Along the northernmost part of the district boundary stands one of Rome's oldest churches, San Lorenzo in Lucina [6].
It stands on the spot where Lucina, an ancient Roman lady, hosted in her own house one of the earliest places of worship for Christian believers, in times when this religion was still proscribed.

bust of Gabriele Fonseca, a work by Bernini
The church, completely rebuilt in the early years of the 12th century, and altered inside in the 1600s, still features its medieval porch and belltower.
The lovers of Gianlorenzo Bernini may wish to visit a chapel in this church, which the great artist drew in his late years for the Fonseca family; on the left side, a lively bust of Gabriele Fonseca (c.1670), the physician of the late pope Innocent X, is featured in the attitude of leaning from a window, a theatrical arrangement adopted by Bernini also in other family chapels he drew.

San Lorenzo in Lucina

The other side of Colonna, i.e. the sloping part, reserves fewer interesting features to the visitor, having been inhabited especially by foreign communities, which could not rely on a large budget. Nevertheless, some elegant houses decorated, either with statues, such as the one featured below, or with paintings, can be found in this half of the district, as well.

building in via Capo Le Case with windows framed by caryatids (1793)
Around 1590 Sixtus V had via Felice [6] opened, presently called via Sistina in his honour, whose purpose was to connect the Pincio Hill with the larger and (in those days) more densely populated Monti district. From the late 18th through the 19th centuries, several figurative artist, as well as many men of letters, chose their Roman residence in this street: the best known ones include sculptor Bertel Thorvaldsen and novelist Hans Christian Andersen, both Danish, Russian writer and playwright Nikolaj Gogol, and among Italian ones, engraver Giovanni Battista Piranesi, his artistic heir Luigi Rossini, the painter and engraver Bartolomeo Pinelli and archaeologist Luigi Canina, who was also an architect (he arranged the ancient Appian Way and widened Villa Borghese).

Sant'Andrea delle Fratte [8] is a church of ancient origin, which up to the first half of the 1500s belonged to the Scottish community of the district, under the original title of Sant'Andrea de Hortis or inter Hortos, literally "amidst the gardens" which stretched on this side of the Pincio.
The name then turned into delle Fratte after the Roman dialect fratte for "bushes". The church was rebuilt in Baroque style around 1650, drawn by Francesco Borromini. It boasts the most bizarre bell-tower in Rome, which stands above via Capo le Case ("Houses End Street", suggesting that the inhabited part of the city ended here).

Bernini's angels in Sant'Andrea delle Fratte:
one bearing the title of the Cross (left)
and one the crown of thorns
The bell-tower has several tiers, with surprising architectural details, worthy of being viewed with a pair of binoculars: the capitals of the small columns of the first tier, with double heads carved on the sides, the angel caryatids of the second tier, and the uppermost flourish, featuring the coat of arms of the Del Bufalo family, topped by a large coronet, celebrating marquis Ottavio Del Bufalo, the sponsor of the making of the church, whose family palace stands nearby, in piazza del Nazzareno.

the bizarre belltower by Borromini

Borromini was also the maker of the large Palazzo di Propaganda Fide, now an extraterritorial property of the Vatican that stands on the other side of the street. Along via di Propaganda Fide, its lintels feature the heraldic bees of the Barberini family, remembering Urban VIII, the sponsor of its making.
As a curious coincidence, in the building that stands on the opposite corner of via di Propaganda Fide dwelt Borromini's great rival, Gianlorenzo Bernini (remembered by a plaque). Sant'Andrea delle Fratte's church holds two beautiful statues of angels carved by him, which originally decorated Sant'Angelo Bridge, together with eight more statues by sculptors of his workshop (see Ponte district).
Cardinal Jacopo Rospigliosi, the nephew of pope Clement IX who had commissioned them, fell in love with these two works; fearing that weathering might have damaged them, he had them left in the artist's studio, where he could admire them at his own disposal. Two faithful replicas were then made, to be set on the bridge, where they are still standing. In 1731, Prospero Bernini, one of Gianlorenzo's grandsons, gave the two statues to the nearby church, where they are kept on display.

Another important landmark in Colonna district, along the boundary with Trevi, is piazza di San Silvestro [9], which was turned into a pedestrian area in 2012. It looks very wide because on one side it continues with the adjacent piazza di San Claudio, from which up to the 1930s it was separated by some buildings, then taken down.
In the Roman age, here stood the Temple of the Sun (273), only scarce traces of which are still extant, particularly a few columns, which can be seen together with other fragments in the courtyard of San Silvestro in Capite's church. The latter was founded over the house of a pope or, better, two: Stephen II, and his brother and successor Paul I (mid 8th century); In the Middle Ages, this area was in fact called Catapauli (i.e. "by Paul").

piazza San Silvestro, with the General Post Office building in the background,
besides which the belltower of San Silvestro in Capite is partly visible

The present shape of the church dates back to the late 16th century, when it was basically rebuilt; the front looking towards the square, instead, was built in c.1700.
The church is not only dedicated to St.Sylvester, but also to St.Stephen (the earliest of the two aforesaid popes): the statues resting above the front feature them, while the title in Capite ("by the Head") sprang from the fact that here the head of St.John the Baptist is held, remembered as well by a frieze in the upper part (right).

← columns ffrom the Temple of the Sun
the courtyard of San Silvestro's church and
the frieze with the Baptist's head →

The very ancient convent annexed to the church, standing right to the latter, in 1878 was completely refurbished and turned into the General Post Office building, which occupies almost the whole northern side of the square, and whose mullioned windows are decorated with round reliefs featuring the portraits of members of the Savoia royal family.