The city lies on the Lambro, a tributary of the Po, 8 miles north-northeast of Milan.
Monza (Modicia) was a minor Roman settlement, selected by the Lombard king Theodoric, for his capital, and its first important associations are with Theodelinda, the Lombard queen. In the Middle Ages, the commune of Monza was sometimes independent, sometimes subject to Milan and the Visconti. In the course of its history Monza stood thirty-two sieges, but the Porta d'Agrate is the only vestige of its walls and fortifications. Nearby is the nunnery in which the nun of Monza (in Manzoni's I Promessi Sposi) was enclosed.
Monza is famous for its Romanesque-Gothic Cathedral of San Giovanni Battista. There Theodelinda's basilica of 590 was enlarged at the close of the 13th century by enclosing the former atrium within the building. The fine black and-white marble facade was erected in the mid-14th century by Matteo da Campione. In the Cathedral Treasury is the Iron Crown of Lombardy, supposed to contain one of the nails used at the Crucifixion. The treasury also contains the crown, fan and gold comb of Theodelinda, and, as well as Gothic crosses and reliquaries, a golden hen and seven chickens, representing Lombardy and her seven provinces. Though the interior has suffered changes, there is a fine relief by Matteo da Campione representing a royal Lombard coronation, and some 15th-century frescoes with scenes from the life of Theodelinda.
The historical centre also contains the church of Santa Maria in Istrada, with a rich terra-cotta facade of 1393, and the Broletto or Arengario, the 14th-century palace of the civic commune, raised on an arcade of pointed arches, with a tall square machiolated tower terminating in a sharp central cone.
Nearby, the royal villa (Villa Reale) originally built by Piermarini in 1777 for the archduke Ferdinand of Austria, lies on the banks of the Lambro, surrounded by its park (the biggest enclosed park in Europe).
At Monza King Umberto was assassinated, July 29, 1900.
The town also hosts a University, a Department of the University of Milan, and a Court of Justice, as well as several Administrative regional offices.