Following his move to London in 1762 Barrett rapidly established himself as the leading landscape artist working in oil paint. In 1764 he was exhibiting at both the Free Society of Artists and the Society of Artists of Great Britain. Barret was awarded the premium prize of 50 guineas for the "Large Landscape with Figures" which he exhibited at the Free Society exhibition in 1764, and this was purchased a year later by the Marquess of Rockingham for £100 guineas. At the Society of Artists he displayed four paintings including views on the Dargle and Powerscourt Waterfall, paintings that he must have brought with him from Ireland.