Brianza (Italian: [briˈantsa], Lombard: [briˈãː(t)sa]) is a geographical, historical and cultural area of Italy, at the foot of the Alps, in the northwest of Lombardy, between Milan and Lake Como.
There, St. Augustine of Hippo (as documented by himself in his Confessions) had lived at Rus Cassiciacum (now Cassago), during the period after his conversion and just before his baptism by Bishop Ambrose.
In the Middle Ages the Cathars, the Humiliati and the Pataria religious movement rose and fell in several towns of Brianza.
The name Brianza may be derived from the Celtic word brig ("hill"), or the Latin name Brigantia which originated from some colonies of the Brigantes, or Brigantii, a Celtic sub-tribe of Alps and Prealps that were Romanized and after the Barbarian invasions emigrated.
According to another tradition, when the Celtic leader Bellovesus founded Milan, his chief lieutenant Brianteo conquered a surrounding geographical area, which was thenceforth named Briantia or Brianza.