He was the second son of Robert Barclay, the Scottish Quaker writer, and was active in the Society of Friends. An apprentice in London in 1698, he became a leading linen merchant. Involved in banking through a family connection with John Freame, father of his second wife, Barclay was not directly concerned with the firm that much later became Barclays Bank; but two of his sons were, John and David Barclay of Youngsbury, who famously manumitted his slaves.[1]