The School has origins in the Grammar School of Dundee founded by the abbot and monks of Lindores Abbey after they were granted a charter by Gregory, Bishop of Brechin, in the early 1220s to "plant schools wherever they please in the burgh". Their rights were confirmed by a Papal Bull conferred by Pope Gregory IX on 14 February 1239. It is from this Bull that the School's Latin motto ""Prestante Domino"", translated as "Under the Leadership of God", is taken.