The area of Brixen has been settled since the Upper Paleolithic (8th millennium BC). Other settlements from the late Stone Age have been found and in 15 BC the area was conquered by the Romans, who had their main settlement in the nearby Säben (Sabiona). They held it until around 590, when it was occupied by Bavarians.
The first mention of Brixen dates to 901 in a document issued by the King of Germany Louis III the Child: in it a territory called Prihsna is assigned to Zacharias, bishop of Säben. As time passed "Prihsna" turned into the current name of Brixen. The bishops moved here from Säben in 992, after the Cathedral had been finished.
In 1039 the Bishop of Brixen, Poppo, was elevated to Pope by emperor Henry III. However his reign lasted for only 23 days. Yet in the same century Brixen became the seat of an independent ecclesiastical principate which, in the following years, struggled for existence against the neighbouring county of Tyrol. In 1115 a first line of walls encircling Brixen was completed.
The bishopric was secularized in 1803 and annexed by the Austrian Empire. After the end of World War I Brixen was annexed by Italy.
The oldest coat of arms dates back to 1297 with the lamb, known then from 1304 as a symbol of the lamb. On 13 November 1928 a shield with the city walls and a gate on the lawn in the upper half and the lamb in the lower was adopted. The emblem is a turned argent lamb with an or halo on a gules background; the right foreleg supports a flag with a gules cross. The emblem was granted in 1966