When William Burn launched a major project of alterations at St Giles' in 1829, the congregation (by then also known as the New North Kirk) vacated the building, returning in 1843.

Ministers including Charles John Brown (who led out the New North Free Church at the Disruption) and Robert Nisbet were notable for their active, evangelistic approach to ministry.

Designed by Hardy & Wight in the Decorated Gothic style, it could house 1,000 worshippers and included a prominent steeple, whose parapet quoted that of the tower of St Giles'.

Castlehill is recorded as a site of a meeting-house for Presbyterians after James VII extended toleration to them in 1687, during a period of episcopacy in the Church of Scotland.

[3] The burgh records for 27 January 1699 show that George Lawson and John Wardrop were given a warrant to take down the Lawnmarket meeting-house and to furnish the north-western division of St Giles' (known as "Haddo's Hole") as a church for its congregation.

Some time between the Restoration and the Revolution, the westernmost division, housing the Tolbooth Kirk, was partitioned into northern and southern parts.

[10] Until its removal and destruction at the end of the 18th century, a Romanesque doorway formed the north entrance to the Haddo's Hole division.

[11] In 1829, major work on St Giles' under William Burn began and the New North Kirk was compelled to vacate the building.

[16][17][a] One New North worshipper, Josiah Livingston, later recalled the Brighton Street Chapel as draughty and acoustically poor.

[22][23] With the completion of Burn's alterations of St Giles', the four internal divisions were reduced to three and the western part was occupied by the Tolbooth Kirk.

[29] In 1870, Nisbet, in an attempt to aid the church's mission, revived the practice of ordaining deacons, which had fallen out of use in the late 18th century.

Chambers sought to remove the church's internal partition walls and create a unified interior for the first time since the 16th century.

At the time, the population of Marchmont was increasingly rapidly and the new church stood at the end of Argyle Park Terrace, which had only recently been completed.

[34][35] Keen to advance the restoration of St Giles', Chambers gifted the congregation a tin tabernacle on Bruntsfield Links as an interim church.

[38][39] Following a competition judged by John MacVicar Anderson, honorary secretary of RIBA, Hardy & Wight were selected as architects for the new church.

[43] From the time of the move, the congregation maintained a presence in its parish by renting the old Merchant Company hall in Hunter Square for use as a mission.

As well as worship, the hall hosted groups such as a mothers' meeting, a girls' club, and a children's church and Sunday school.

In 1892, the Merchant Company sold the property to the Royal Bank of Scotland and the congregation purchased mission premises at 128 High Street.

West St Giles' was demolished in 1974 and replaced by a block of flats built for the Viewpoint Housing Association to a designs of Michael Calthrop & Campbell Mars in 1979.

[48][49] The flats provide sheltered accommodation for the elderly and some of the building's early inhabitants had been congregants of West St Giles'.

The interior is spacious, and shows a nave, aisles, and transepts, the arcade resting upon polished columns of red granite.

[45] A refurbishment took place in 1912, including the upgrading of the heating system, the replacement of the gas lights with electric, the overhaul of the organ, and the addition of a new vestry.

[60] Other features saved at the building's demolition include two stone rams' heads from the exterior, which were incorporated into the boundary wall of Hermits and Termits in St Leonard's.