The Pinacoteca is the result of the efforts of a group of upstanding Milanese citizens who wished the City of Milan to be in possession of its own art collection. The drafting of the will and testaments of Fogliani-Marchesi (1861), Innocenzo and Gian Giacomo Attendolo Bolognini (1863) and that of Antonio Guasconi (1863-1865) constituted the first founding steps towards this goal, on the heels of which followed donations, depositi/loans and legacies throughout the second half of the 1800s.

The Art Gallery officially came into being in 1878 with the inauguration of the Museo Artistico Municipale (Municipal Art Museum), housed within the Salon of the public gardens. However, the history of the Gallery began just over a century ago, when the Municipal collection was transferred to the prestigious setting of the Sforza Castle and on the 10th May 1900, the Museo Archeologico e Artistico (Museum of  Archaeology and the Arts) opened to the public.

The expansion of the collection

Over the course of the 1900s the museum was continually expanded by the liberal generosity of numerous local benefactors. The Town Hall itself decided to invest substantial sums to conserve fundamental parts of the city's heritage (Trivulzio Collection, 1935) or to redress notable absences through targeted acquisitions.

The policy of consolidating the collection, reached particular heights on the occasions of the reopening of the museum following the Second World War and more recently, with the acquisitions of Canaletto's landscapes (1995) and Bellotto (1998). The latest expansion was by courtesy of the collector, Amedeo Lia, who in 2007 donated a devotional painting of exceptional value, as it presents an iconographic testament of the Sforza Castle, as painted by a pupil of Leonardo.