He was born in Pont-à-Mousson, Lorraine, France, where his Scottish-born father, William Barclay, held the chair of civil law.

Barclay had persistently maintained his Scottish nationality in his French surroundings, and probably found in James VI and I's accession an opportunity which he would not let slip.

A so-called "fourth part," with the title of Icon Animorum, describing the character and manners of the European nations, appeared in 1614.

[1] He appears to have been on better terms with the Church and notably with Robert Bellarmine, for in 1617 he issued, from a press at Rome, a Paraenesis ad Sectarios, an attack on the position of Protestantism.

The literary effort of his closing years was his best-known work the Argenis, a political romance, resembling in certain respects the Arcadia of Philip Sidney, and the Utopia of Thomas More.

[1] Richard Crashaw's poem, "Description of a Religious House and Condition of Life", beginning, "No roofs of gold o'er riotous tables shining,/Whole days and suns devour'd with endless dining;" was translated "Out of Barclay.