Leighton lived through one of the most turbulent periods in Scottish history. His grandfather was a Pre-Reformation Catholic; his father, Doctor
Alexander Leighton, was tortured during the reign of
King Charles I for his Presbyterian beliefs after authoring a pamphlet, ''Zion's Plea against Prelacy'', in which he criticised the church, condemning bishops as "anti-christian and satanic". Robert became an archbishop during one of the periods when the Church of Scotland was episcopal. Robert Leighton was born in
London to
Scottish parents in 1611. Robert Leighton's mother was Alexander Leighton's first wife. According to
Gilbert Burnet, Leighton was distinguished for his "saintly disposition" from his earliest childhood, despite the persecution of his family. In 1627 (before his father published his pamphlet) at the age of sixteen, Robert Leighton went to study at the
University of Edinburgh, graduating with an
MA in 1631. Following his graduation, his father sent him to travel abroad, and he is understood to have spent several years in
France, where he acquired a complete mastery of the
French language. While there he passed a good deal of time with relatives at
Douai who had become Roman Catholics, and with whom he kept up a correspondence for many years afterward. Either at this time or on some subsequent visit he had also a good deal of intercourse with members of the
Jansenist party. This intercourse contributed to the charity towards those who differed from him in religious opinion which ever afterward formed a feature in his character. ==Church career==