[1] In the mid 1790s, the rector of St Chad's, Father Rowland Broomhead decided to set-up a second chapel in Manchester.

He purchased a plot of land near Deansgate and quickly set about the task of building a new church, which opened on 30 November 1794, and was dedicated to St Mary.

Contrary to popular local myth, St Mary's was never built in secret or to be hidden, in fact the opening was announced in the local newspapers and Mulberry Street in the 1790s was a busy residential and commercial thoroughfare opening out onto Deansgate.

[citation needed] The architect chosen to oversee the work was Matthew Ellison Hadfield, who later went on to build Salford Cathedral and the new St Chad's Church, Cheetham Hill.

The church's design is a blend of Norman, Gothic and Byzantine detail; Pugin himself said that the building "shows to what depth of error even good men fall, when they go whoring after strange styles.

"[4] Externally, the Hidden Gem is built of plain red brick, with an ornate bell tower, stone-dressed church windows, and an entrance marked out with a fine stone doorway, which is finely carved and depicts two Angelic Hosts bearing a medallion of Agnus Dei.

Et adoremus in loco Sancto eius" a construction of two bible verses: "Come, let us go up to the mountain of the Lord",(Isaiah 2:3) and "Praise Him in His Holy places".