Each structure was rebuilt a number of times but originated from a single Etruscan temple, built to honor the truce of the Sabine conflict.

On July 10, 1923, the Italian government acquired the Curia Julia and the adjacent convent of the Church of S. Adriano from the Collegio di Spagna for approximately £16,000.

[8] That allowed archaeologists to date repairs made to the Senate House and the addition of the bronze doors to the reign of Emperor Domitian (AD 81–96).

The original appearance of the Senate House is known from an Emperor Augustus denarius of 28 BC, which shows the veranda held up by columns on the front wall of the building.

The altar was placed in the Curia by Augustus to celebrate Rome's military prowess, more specifically his own victory at the Battle of Actium, in 31 BC.

The altar was removed in 384 AD, as part of a general backlash against the pagan traditions of Ancient Rome after the rise of Christianity.

That is described by Claridge as " stylized rosettes in squares alternate with opposed pairs of entwined cornucopias in rectangles, all worked in green and red porphyry on backgrounds of Numidian yellow Phrygian purple".

[11] In fact, the relinquishment of power was truer in word than in deed; the construction of the Curia Julia coincided with the end of Republican Rome.

In the past, the Curia Hostilia and Comitium "were oriented by the cardinal points of the compass, which may have marked them out as specially augurated space and at any rate set them off obliquely from the Forum rectangle that formed over the centuries".

The reduced power of the Roman Senate during the Imperial Period is reflected by the Curia Julia's less prominent location and orientation.