"When I returned to Rome from Gaul and from Spain, in the consulship of Tiberius Nero and Publius Quintilio, having brought to a satisfactory finish my works in these provinces, the Senate decreed that there should be consecrated in the Field of Mars an altar to the Augustan Peace and ordered that the officials, priests and vestal virgins should celebrate a sacrifice at it every year."
The ceremonial dedication of the Altar of Peace, took place on the 30th January in the year 9 B.C.
It seems, according to the evidence provided by the historian Cassius Dione (LIV, 25.3), that at first the Senate had planned to build an altar within their own building, the Curia, but the idea was not followed through and the northernmost part of the Field of Mars, which had recently been urbanised, was chosen instead. The altar dedicated to peace came, therefore, and not by chance, to be built in the middle of a vast plain, on which, traditionally, the manoeuvres of the infantry and the cavalry took place, and, in more recent times, the gymnastic exercises of the Roman youth.