Greyfriars Kirk maintains St Oran's tradition of Gaelic worship in Edinburghto the present.

The Horse Wynd building stood on a rectangular plan and was executed in a plain neoclassical style.

The Kirk's requirement that there could be only one place of worship in each parish also complicated the establishment of an extra-parochial Gaelic chapel.

[2][3] The General Assembly did, however, make provision for Gaelic preaching in Edinburgh in 1704; nevertheless, this could not be effected due to the lack of a Gaelic-speaking minister.

[7] After McVicar's death in 1747, army chaplains based at the Castle may have maintained Gaelic worship until Dugald Buchanan's arrival in Edinburgh in 1765.

[4] Though a layman, Buchanan gathered round him a Gaelic-speaking congregation which met at College Street Relief Church in the Southside.

In 1766, some prominent Edinburgh citizens, led by burgess William Dickson, issued an appeal to create a formal Gaelic chapel.

[10] The Society in Scotland for Propagating Christian Knowledge was responsible for nominating preachers while the chapel came under the jurisdiction of Old Greyfriars kirk session and was managed a group of twelve deacons.

[16][18] McDonald was so popular a minister that, in 1813, his final service was held in the West Kirk, the congregation being too large for the Gaelic Chapel.

[26] At the Disruption of 1843, the vast majority of the congregation, including all its office-bearers, joined the Free Church.

[29] The Edinburgh Improvement Act of 1867 provided for the creation of Chambers Street, which required the demolition of the Horse Wynd chapel.

The congregation vacated the Horse Wynd building the following year and worshipped nearby at the Protestant Institute on George IV Bridge until 1875, when they purchased the former Catholic Apostolic church on Broughton Street.

Responding to reports of the declining use of Gaelic in the worship of Highland parishes, the Gaelic church's minister, Donald Tolmie Masson, wrote to the editor of The Scotsman in April 1896: All these dreary three-and-forty years I have been preaching to my countrymen in this city in their native tongue, and my voice has been vox clamantis in sicco.

[33]In response, another correspondent, writing under the name "Argyle Square", noted that, though the church had been well-attended forty years prior, the move to Broughton Street had affected its congregation.

The correspondent nevertheless attributed the bulk of the congregation's decline to Masson's "dry manner and cold reserve".

[34] Masson wrote two further letters to The Scotsman to defend himself against these accusations and against another correspondent named "Highland Churchman".

[35][36][37] Likely motivated by the union of the Free and United Presbyterian churches in 1900, the congregation that year adopted the more distinctive name of "St Oran's".

[40][41] In the years prior to James Duff MacDonald's death in 1945, the church's membership had begun to tail off.

In this context, the General Assembly concluded the maintenance of two small, Gaelic-speaking congregations in the city was unnecessary and, from 1930, sought to unite the charges.

[43] Summarising the contrasting histories of Edinburgh's two Gaelic congregations, J. Boog Thomson, session clerk of St Oran's, told The Scotsman at the time: We represent a minority in the Presbytery by blood and tradition, and many of us by language.

St Columba's are not only mainly representative of the Free Church, but were drawn and recruited from Ross and Cromarty and the fringe of Inverness.

St Oran's were recruited mainly from Argyll, with a large predominance of Campbells, Shaws, and Macdougals.

St Columba's congregation walked out in 1842, [sic] and since then there has been intermittent litigation as to the return of the funds and property.

[44][45] The united congregation adopted the name "Highland Church" and used the St Columba's buildings.

There were four windows on the chapel's east side, glazed with lozenge panes in the bottom and with shutters for ventilation at the top.

[12] Plans submitted to the Dean of Guild's court show the Horse Wynd chapel as a simple Neoclassical building.

The walls were capped by a simple cornice and short attic storey while a pitched roof covered the building.

The plan shows the flank of the building as consisting of a simple wall of four bays and two storeys with segmental-arched windows.

[55] In 1821, the congregation purchased two silver communion cups with the effects of Sergeant John Munro of the Royal Scots and inscribed "DA CHOTHEN GHAELIC DHUNEIDIN A REIR THIOMNUIDH SHERGt.