The church was rendered the only bomb-proof building at the time, in the Fort, on account of a peculiarly designed roof, details of which are provided under Architecture.

[5] On account of its peculiar roof-structure, the church was used as a barrack and granary between December, 1758 and January, 1759 during the Second Carnatic War, when the French besieged Madras and again when Hyder Ali invaded the town in the late 18th century.

At the west end of the nave is a spacious gallery, resting on carved Burma teak pillars, which originally housed the seat for the Governor.

Though it now has a tower to the west of the nave, this was not part of the original design but was rather added at the end of the seventeenth century on the orders of Sir John Goldsborough.

The altar piece, a depiction of the Last Supper, is unsigned but is said to portray obvious signs of the Raphaelite school, and it is supposed that Raphael himself painted the central figures.

Originally, no church-yard existed and all those who died in the fort were buried in the Guava Garden, that adjoined the Governor's House in the 17th and early 18th centuries.

Therefore, on the petition to the Select Committee of Sir John Call, the Chief Engineer of the fort, the cemetery was re-located to the north-west of the island, while the tomb-stones were brought and placed around the church.

When the Capuchin Church of St. Andrew was demolished subsequent to the Peace of Aix-la-Chapelle, many of the tomb-stones were brought here, thus explaining the large numbers of Roman Catholic grave-stones, inscribed in Latin and Portuguese.

His later gift of money to Cotton Mather helped in the foundation of Yale University in the United States of America.