Now considered the “religious heart” of Santa Maria del Monte, the Sanctuary was founded between the 8th and the 9th century AD. The original building had simple and linear shapes; to notice were the only nave and the apse. In 1100 the number of believers who visited the Sanctuary multiplied and the building was enlarged: the walls of the old church were knocked down and the apse was appropriately restored.
In 1472 the Duke of Milan Galeazzo Maria Sforza decided to renovate the building again: the Romanesque apse was demolished and the ancient façade was replaced by a stone colonnade (1518).
In 1600 the Church of S. Giacomo was definitively knocked down and the nave of the Sanctuary was extended.
In 1671 was erected the “Cappella delle Beate”, consecrated to Caterina Moriggi and Giuliana Puricelli; the frescoes were painted by Antonio Busca.