It and the connected Archdiocese main buildings form the eastern side of Place du Canada, and occupies a dominant presence on Dorchester Square.

His choice to create a scale model of Saint Peter's Basilica in Rome was in response to a rivalry with the Sulpician order who had been the feudal seigneurs of Montreal, and with the Anglican Church, both of which favoured the Neo-Gothic style instead.

The site also sparked controversy due to its location in the western part of downtown, in a then predominantly English neighbourhood far from the homes of the French-Canadian church-goers.

At the time, the Holy See and the Papal States were threatened by the nationalist troops of Victor Emmanuel II, king of Piedmont, who was attempting to assert control over all Italy.

The undeterred bishop Bourget reacted to these events by sending a total of 507 Canadian Zouaves to defend the Papal territories in Italy, whose names are engraved in gold letters on the marble slabs in the cathedral.

A painting depicting Colonel Athanase de Charette, commander of the Papal Zouaves, was made in 1885 by Lionel Royer.

Joseph Michaud, the chaplain of the Papal Zouave volunteers of Montreal, was sent to Rome to secretly produce a scale model to work from.

It was rededicated in 1955 to Mary, Queen of the World, by Pope Pius XII at the request of cardinal Paul-Émile Léger.

This work of art features a wood-carved altarpiece, decorated with gold leaf and framing a painting depicting the Assumption of the Virgin Mary.

When the monks were forced to leave during the religious retaliation, the occupying French troops sold all the precious furniture in the Abbey.

At the beginning of the 20th century, the Austrian architect-conservator Rodolphe Messmer discovered the altarpiece in the church of Suarce, France and acquired it.

The aisles of the nave and the arches in the transept contain painting depicting historical events in the early days of Montreal (called Ville-Marie at the time).

Since the building was originally dedicated to Saint James the Greater (and it still is), it explains why most of the Latin texts refer to his life.