Landscape painting has occupied such a dominant position in the history of Irish art that it would be easy to imagine this genre had always enjoyed favour here. In fact, landscape only emerged as a popular form in Ireland towards the middle of the 18th century.

It had long been a regular subject for artists elsewhere in Europe, where the classical ideal perfected by Poussin and Claude Lorrain - French artists working in Italy - had established a dominant style in the mid-17th century. The political turmoil in Ireland during that period meant no such tradition could develop here and it was only once the country became more settled after 1700 that painters of landscape began to be patronised. One of the earliest and most successful of these was George Barret, examples of whose work still regularly come up for sale in auction rooms. Barret was born in Dublin, probably in 1732, and originally, like his father, he worked in the clothing business. However, eventually he became a pupil of Robert West at the Dublin Society's School, where he won a first prize in the annual examination show. It would seem that his interest in landscape art was encouraged from the start and, having left school, he began specialising in this genre.

What sets George Barret apart from many of his contemporaries is that he painted real rather than idealised views. In this study of nature, the artist was encouraged by Edmund Burke who, it is believed, first introduced him to the landscape around the Powerscourt estate in Co Wicklow, including its famous waterfall and the Dargle. As Professor Anne Crookshank and the Knight of Glin have pointed out in The Watercolours of Ireland (1994), Barret's "early oil paintings and his etching of the Dargle adhere to Burke's ideas on the Sublime where he emphasises the importance of cloudy skies, dark and gloomy mountains and vast cataracts". Many pictures possess an exceptionally high degree of topographical and botanical accuracy. By concentrating on natural scenery at its most awesome and spectacular, Barret was in effect a proto-Romantic of the kind much more common in the following century, and he was certainly a precursor of later Irish landscape artists such as Thomas Roberts and William Ashford.

He wrote that "the study of art and nature must go hand in hand," which was an unusual opinion to express in the mid-18th century, when the ideal - and the artificial - were still greatly admired.

Not that Barret never lapsed into this style of landscape painting. The National Gallery of Ireland possesses 16 of his oils showing Italian scenes which were originally painted for Russborough, Co Wicklow, the home of Joseph Leeson, first Earl of Milltown. As Michael Wynne points out in The Irish Arts Review, Volume 10 (1994), some of these pictures were copies of works brought back by Leeson from Rome. Crookshank and Glin's 1978 The Painters of Ireland, c.1660-1920, notes the very variable quality of Barret's art, and this is certainly evident in some of the pictures attributed to him which come up for sale.

In 1762, having failed to win support for the publication of four engravings of Powerscourt and the Dargle, he moved to London and quickly won many new clients - at one stage, he was said to have an annual income of £2,000, which was very substantial for an artist of the time. The result was that he was often overworked; as Crookshank and Glin remark, "he must have painted an enormous number of pot-boilers. There are, for example, many Claudian scenes which bear his name and are usually less than interesting."

Barret's paintings can be formulaic, with a reliance on the same delicately foliaged clusters of trees beneath lowering skies. His principal rival, the Welsh landscape painter Richard Wilson, described Barret's foliage as being "spinach and eggs", a comment which mixes professional pique with an element of the truth. Actively instrumental in the foundation of the Royal Academy in London and one of its founder members (he exhibited there regularly until 1782), Barret, despite his success, was reduced to bankruptcy through poor handling of his business affairs.

His last years were spent as Master Painter to the Chelsea Hospital, a position secured for him by his old friend Edmund Burke, Barret died in May 1784. Several of his children subsequently became artists. As he was so prolific, Barret's paintings tend to come onto the market regularly. The highest price paid for one of his works was made in January 1994 when the The Dukes of Cumberland and York driving a landau in Windsor Great Park was sold by Sotheby's in New York for £154,362. However, the sums paid for Barret's landscapes are customarily much lower; in May 1998, his Crossing a Stream fetched £19,550 and at the same auction house's Irish sale this year, Barret's Cattle in a Clearing, a Church beyond went for £3,450.