Mechanized Brigade (Portugal)

The Nun Alvares Division adopted an almost totally U.S. organization (and equipment), including around 20,000 men, with three infantry regiments (each reinforced with a squadron of tanks), a divisional tank battalion, three field artillery battalions and anti-aircraft, engineering, signal and logistical units.

To serve as a training base for the division, the large Santa Margarida Military Camp was built.

From 1961, the Portuguese Army's effort focused primarily on the Overseas War, with the division entering a decline.

In 1968–1976, studies were carried out to update Portugal's ground contribution to NATO for a force of different characteristics from the 3rd Division.

This took form with the 1st Independent Composite Brigade (1ª Brigada Mista Independente, 1ª BMI), established in 1976.