Severus’s relations with the Roman Senate are never good.

He is unpopular with them from the outset, having seized power with the help of the military, and he returns the sentiment.

Severus has ordered the execution of dozens of Senators on charges of corruption and conspiracy against him, replacing them with his own favorites.

Although his actions have turned Rome into a military dictatorship, he is popular with the citizens of Rome, having stamped out the rampant corruption of Commodus's reign.

When he returned from his victory over the Parthians, he erected the Arch of Septimius Severus (Italian: Arco di Settimio Severo) in Rome.

The elaborate white marble arch, situated at the northwest end of the Roman Forum, is a triumphal arch dedicated in 203 to commemorate the victories of the Emperor and his two sons, Caracalla and Geta, in the two campaigns against the Parthians of 194/195 and 197-199.

The arch is raised on a travertine base originally approached by steps from the Forum's ancient level.

The central archway, spanned by a richly coffered semicircular vault, has lateral openings to each side archway, a feature that will copied in many Early Modern triumphal arches.

The three archways rest on piers, in front of which are detached composite columns on pedestals.

Winged Victories are carved in relief in the spandrels.

A staircase in the south pier leads to the top of the monument, on which are statues of the emperor and his two sons in a four-horse chariot (quadriga), accompanied by soldiers.

Severus begins an ambitious public works project in Rome, laying the foundation for the largest and most richly decorated public baths ever built.

Plans call for a massive (702 x 360 feet/211 x 108 meters) central building and an enormous square enclosure (1,500 x 1,500 feet/450 x 450 meters) lined with art galleries, gymnasia, nymphaea (wall fountains), shops, and two libraries.

The greater part of the Flavian Palace overlooking the Circus Maximus is undertaken in Severus’s reign, as is the Septizodium, located at the place where the Via Appia leads to the Palatine.

The origin of the name "Septizodium" is unclear; the Septicozium was probably named for the seven planetary deities (Saturn, Sun, Moon, Mars, Mercury, Jupiter, Venus or for the fact that it was originally divided into seven parts.

The building has no known practical purpose and was probably meant to be a decorative façade.

Other examples of septizodium are known, all from Africa.

Ammianus Marcellinus, writing in the fourth century, refers to the building in an ambiguous passage: "The plebs...had come together at the Septemzodium, a popular place, where Marcus Aurelius built a Nymphaeum in a rather ostentatious style."