The Portuguese were the earliest European traders in India and they had been in Bengal a hundred years before the British. They first settled near the bank of the River Hoogly and founded the town of Hoogly, nearly sixty years before Calcutta was founded. The presence of Portuguese merchants in Calcutta is also recorded far before the coming of British merchants. During those early days they used to pray in a mud hut. However, with the view to increase European population in the locality, the British Company allotted them10 bighas of land to the Roman Catholics of the Augustinian order to set up a Mass Hall in the area.

But, Sir John Goldsborough of the East India Company soon realized that the Mass Hall is being used to convert the company’s Protestant members to Roman Catholicism and arrange their marriages with the native women. In 1693, he ordered to immediately vacate them, but they bounced back within six months, after the death of Goldsborough. Before 1700, at the expense of Mrs Margaret Tench, a brick-built structure was constructed a little further away from the original Mass Hall, to be used as their place of worship. Under the direction of Vicar Fari Francisco d’Avsumpaco, the Chapel was much enlarged in 1720 by Mrs. Sebastian Shaw. The tombstones of these two pious ladies now lie on each side of the altar in the present Church of the Virgin Mary of Rosary. However, after the complete destruction of the St. Anne’s Church by Nawab Siraj Ud Daulah in 1756, the British took over the Portuguese Chapel and began to conduct services there. Nevertheless, after three years, the Chapel was again handed over to the Portuguese by the order of the Court of Directors in London.

Since 1759, the Portuguese community of Calcutta was contemplating to construct a new dignified building for their church and finally in 1796 they decided to pull down the old church building and construct a more spacious and elegant one. A fund for the proposed construction was raised and the major portion of the fund was contributed by two Bombay based opulent brothers and well known Portuguese traders, Joseph and Luis Barretto. The building was designed by James Driver and the first stone of the new church was laid on the 12^th day of March 1797. The construction of the shrine was completed within three years and the new edifice with its two graceful towers, capped with crown shaped cupolas, was consecrated and dedicated to Rosary Virgin Mary on the 27^th of November, 1799.

Located on the Portuguese Church Street, just at the crossing of Brabourne Road and Canning Street alias BRB Bose Road, the Portuguese Church was formally known as The Cathedral of the Most Holy Rosary. Adorned with a decorated pediment, supported on both sides by two uncommon domed towers and an extended portico with arched entrance way, the Cathedral was built in typical Catholic style.

The long and majestic colonnaded corridor leads to the beautifully decorated alter flanked with intricately decorated circular stained glass windows. The confession boxes are lined along the walls with the statues of Jesus, Mary, Joseph and various other Biblical characters, apart from the fairies and the angles. A number of memorial tablets are affixed on the walls are adorned with a number of memorial tablets, which include one to Archbishop of Calcutta, Paul Goethals, a Belgian who was Archbishop of Calcutta from 1886 to 1901. He had a wonderful collection of books, which he donated to the Jesuit Fathers of St. Xavier's College on Park Street.

The star attraction of the Portuguese Church is the 14 Stations of the Cross, also known as the Way of Sorrows or Via Crucis. It refers to a series of images depicting Jesus Christ on the day of his crucifixion and accompanying prayers. There is a beautiful statue of the Virgin Mary behind the altar, while the mortal remains of the first Archbishop of Calcutta lie below the altar. The Portuguese Church is also the final resting place for one Mrs. Mary Carey, who is supposed to be a survivor of the so called Black Hole Tragedy.