The Reformed Presbyterian Church of Scotland is a small, Scottish, Presbyterian church denomination. Theologically they are similar to many other Presbyterian denominations in that their office-bearers subscribe to the Westminster Confession of Faith. In practice they are more theologically conservative than most Scottish Presbyterians and maintain a very traditional form of worship. In 1690, after the Revolution, Alexander Shields joined the Church of Scotland, and was received along with two other ministers. These had previously ministered to a group of dissenters of the United Societies at a time when unlicensed meetings called conventicles were outlawed. Unlike these ministers, some Presbyterians did not join the reconstituted Church of Scotland. From these roots the Reformed Presbyterian Church of Scotland was formed. It grew until there were congregations in several countries. In 1876 the majority of Reformed Presbyterians, or RPs, joined the Free Church of Scotland, and thus the present-day church, which remained outside this union, is a continuing church. There are currently Scottish RP congregations in Airdrie, Stranraer, Stornoway, Glasgow, and North Edinburgh. Internationally they form part of the Reformed Presbyterian Communion.
Chambers’s Encyclopaedia describes the Cameronians being official designated, Reformed Presbyterians. It continues — no doubt, the principles of the body are those for which Cameron contended and died; but it assumed no distinct form till after the Revolution of 1688; and it might briefly be defined as consisting of a small party of Presbyterians, who objected to the Revolution settlement in church and state, and desired to see in full force that kind of civil and ecclesiastical polity that prevailed in Scotland from 1638 to 1649. According to the Solemn League and Covenant, ratified by the parliaments of England and Scotland, and also by the Assembly of Divines at Westminster in 1643, Presbyterianism was to be maintained in the kingdoms of England, Scotland, and Ireland, and popery, prelacy, superstition, heresies, schism, &c., were to be extirpated. The Covenanters in Scotland contended, as is well known, under much suffering, for this species of Presbyterian supremacy throughout the reigns of Charles II and James VII. As a measure of pacification at the Revolution, Presbytery was established in Scotland by act of parliament 1690; but it was of a modified kind. Substantially the church was rendered a creature of the state, more particularly as regards the calling of General Assemblies; and equally to the disgust of the extreme party whom we refer to, prelacy was not only confirmed in England and Ireland, but they saw that there was a general toleration of heresy — i. e., dissent. In sentiment, if not in form, therefore, this uncompromising party repudiated the government of William III and his successors, and still maintained the perpetually binding obligations of the Covenants. (For the historic view of other Scottish Presbyterians see Fentiman) Unquestionably, these Cameronians acted under strong convictions, and only desired to carry out to a legitimate issue those principles which have always mingled with the theories of the Presbyterian Church of Scotland; but which, for prudential considerations, have been long practically in abeyance. In short, it is in the standards of this sect that we have to look for a true embodiment of the tenets held by the great body of English and Scotch Presbyterians of 1643. Others gave in to the Revolution settlement, and afterwards found cause to secede. The Cameronians never gave in, and of course, never seceded. 
Although thus, in point of fact, an elder sister of the existing Church of Scotland and all its Secessions, the Cameronian body, as has been said, did not assume a regular form till after the Revolution; and it was with some difficulty, amidst the general contentment of the nation, that it organised a communion with ordained ministers. The steadfastness of members was put to a severe trial by the defection of their ministers; and for a time, the people were as sheep without a shepherd. At length, after their faith and patience had been tried for 16 years, they were joined by the Rev. John M’Millan, from the Established Church, in 1706. 
In a short time afterwards, the communion was joined by Mr. John M’Neil, a licentiate of the Established Church. As a means of confirming the faith of members of the body, and of giving a public testimony of their principles, it was resolved to renew the Covenants; and this solemnity took place at Auchensach, near Douglas, in Lanarkshire, in 1712. The subsequent accession of the Rev. Mr. Nairne, enabled the Cameronians to constitute a presbytery at Braehead, in the parish of Carnwath, on 1 August 1743, under the appellation of the Reformed Presbytery. Other preachers afterwards attached themselves to the group, which continued to flourish obscurely in the west of Scotland and north of Ireland. For their history and tenets, we refer to the Testimony of the Reformed Presbyterian Church. (See For a modern summary see)
Holding strictly to the Covenants, and in theory rejecting the Revolution settlement, the political position of the Cameronian is (says Chambers) very peculiar, as they refuse to recognise any laws or institutions which they conceive to be inimical to those of the kingdom of Christ; from which cause they have greatly isolated themselves from general society, and refused several of the responsibilities and privileges of citizens. At the same time, it is proper to say, that if zealous and uncompromising, they are also a peaceful body of Christians, who, under the shelter of a free and tolerant government, are left unmolested to renew the Covenants as often as fancy dictates. In 1860, the body numbered 6 presbyteries, comprising altogether 45 congregations in Scotland, one of which was in Edinburgh and 4 in Glasgow. Connected with the body, there are congregations in Ireland and North America.