[3] Today, it is home to a large congregation in the conservative evangelical tradition with a ministry to city workers, families, students and young professionals.

Four English-speaking (and one Mandarin-speaking) church services take place each Sunday, as well as a number of midweek talks and small group Bible studies.

Although it is thought that a Roman or a Saxon building might have stood on the site, the first mentions of the parish church of St Helen's date back to the mid-12th century.

[6][7] The church was divided in two by a partition running from east to west, the northern half serving the nuns and the southern the parishioners.

In 1480, four great arches were installed between the nun's choir and the parishioner's nave, and a wooden screen was put in place to separate the two.

In the following years, the building was rearranged according the principles of the Reformation, which put the emphasis on the preaching of the Word and on the full and active participation of the congregation.

This restoration was inspired by the Oxford movement, which advocated moving the centre of importance in the church from preaching to the sacrament of the Eucharist.

This new arrangement resulted in a new floor with levels gradually ascending from the west to a new high altar in the east, completed by an ornated reredos and marble pavement, once again enclosed in a chancel by a neo-Gothic screen.

The church was left undamaged by the Blitz during World War II[9] and it was designated a Grade I-listed building on 4 January 1950.

The floor was evened out and returned to its original level, which allowed for the installation of underfloor heating, a sound reinforcement system and a baptistry in front of the pulpit.

A new gallery was erected on the west end to provide additional seating and house the organ, now returned to its original position.

The principles of this restoration sought to arrange the building once again around the preaching of the Word and strip it down of the ritualistic elements added in Victorian times, following the needs of the large Evangelical congregation.

It subsequently stated that episcopal oversight at St Helen's will henceforth be provided by Bishops from the Global Fellowship of Confessing Anglicans (GAFCON) and its affiliated denominations.

The service was led by Bishop Rod Thomas, the retired provincial episcopal visitor for conservative evangelical, and involved the laying on of hands.

The present building is the result of a substantial restoration in 1993–1995 by architect Quinlan Terry, after consistent damages were incurred by two IRA bombs in 1992 and 1993.

It has undergone several restorations since by builders such as George Pike England in 1810, J. C. Bishop and Son in 1910 and 1923, Hill, Norman and Beard in 1929 and 1957 and Martin Goetze & Dominic Gwynn in 1996.