Barclay, the representative of an ancient family formerly called Berkeley, was born in 1610, and served under Gustavus Adolphus. On the outbreak of the civil war he accepted a commission in the Scotch army. He was a friend of John, afterwards Earl Middleton, who had also served in the thirty years' war. Barclay commanded part of the force with which Middleton repelled Montrose before Inverness in May 1646. On 26 Jan. 1648 he married Catherine, daughter of Sir R. Gordon, and bought the estate of Ury, near Aberdeen. During Hamilton's invasion of England in the same year he was left in a command at home; but retired, or was dismissed, from active service when Cromwell entered Scotland after Preston. We are told that Barclay and Middleton were ‘always on that side which at least pretended to be in the king's interest.’ Barclay's estate was forfeited, and, in order, it is said, to regain possession, he obtained a seat in the Scotch parliament after the death of Charles, and was also one of the thirty members for Scotland returned to Cromwell's parliament of 1654 and 1656 (Acts of Scotch Parliaments, iii. part ii.) He was also a commissioner for the forfeited estates of the loyalists. He was arrested after the Restoration, apparently in 1665 (see a warrant for his committal to Edinburgh Castle, 23 Aug. 1665, in Additional MS. 23123); but was released by the interest, it is said, of his friend Middleton.
He had lost his wife in 1663, and at her dying request recalled his son Robert, who had been sent for education to his uncle, then rector of the Scotch college at Paris. The father was afraid of catholic influences, and the son tells us (treatise on Universal Love) that he had in fact been ‘defiled by the pollutions’ of popery. He obeyed his father's orders, and returned at the cost of losing the promised inheritance of his uncle, and for a time remained in an unsettled state of mind. His father was converted to quakerism, through the influence, it is said, of a fellow-prisoner in Edinburgh, James Swinton, and declared his adhesion to the sect in 1666. Robert Barclay followed his father's example in 1667. He studied hard at this time; he learned Greek and Hebrew, being already a French and Latin scholar, and read the early fathers, and ecclesiastical history. In February 1670 he married one of his own persuasion, Christian, daughter of Gilbert Mollison, an Aberdeen merchant, by his wife, Margaret, an early convert to quakerism. He soon afterwards turned to account a degree of learning and logical skill very unusual amongst the early quakers in controversy with one William Mitchell, a neighbouring preacher. ‘Truth cleared of Calumnies’ appeared in 1670, and ‘William Mitchel unmasqued’ in 1672. In 1673 he published a ‘Catechism and Confession of Faith;’ and in 1676 two controversial treatises. The first of these, called the ‘Anarchy of the Ranters,’ was intended to vindicate the quakers from the charge of sympathy with anarchy, whilst repudiating the claim to authority of the catholic and other churches. The second was the famous ‘Apology.’ Barclay had already put forth ‘Theses Theologiæ,’ a series of fifteen propositions referring to quaker tenets. They were printed in English, Latin, French, Dutch, and divines were invited to discuss them. A public discussion took place upon them (14 March 1675) in Aberdeen with some divinity students. It ended in confusion, and conflicting reports were published by the opposite parties. The ‘Apology’ itself, which is a defence of the ‘Theses,’ was published in Latin at Amsterdam in 1676. A copy of it was sent in February 1678 to each of the ministers at the congress of Nimeguen; and an English version was printed in the same year. It provoked many replies, and has been frequently republished.
Meanwhile Barclay was suffering persecution at home. In 1672 he had felt it incumbent upon him to walk in sackcloth through the streets of Aberdeen, though at the cost of grievous agony of spirit (Seasonable Warning to the People of Aberdeen). He was imprisoned at Montrose in the same year. In 1676 he travelled in Holland and Germany, and there made the acquaintance of Elizabeth, Princess Palatine, who had taken an interest in quaker principles. She was, it seems, distantly related to him through his mother. He heard during his journey of the imprisonment of his father and some thirty other quakers in the Tolbooth at Aberdeen. He returned with a letter from the princess to her brother, Prince Rupert, asking him to use his influence for the prisoners. Prince Rupert, however, was unable to speak to the king on account of a ‘sore legg.’ Barclay obtained an interview with the Duke of York, afterwards James II, and the king gave him what he calls ‘a kind of a recommendation,’ referring the matter to the Scotch council. The council declined to release the prisoners unless they would pay the fines and promise not to worship except in the common form. Barclay returned to Ury, and was himself imprisoned in November 1676 (see letters in Reliquiæ Barclaianæ). His father had apparently been released on parole (Besse's Sufferings of the Quakers). Robert was released in April 1677, after a confinement