In 1879, Lawson married the artist Constance Phillip, daughter of the renowned sculptor John Birnie Phillip. Although he retained a large studio in Chelsea, where he completed much of his subsequent work, the couple moved to Haslemere in Surrey and, at nearby Blackdown, Lawson created The August Moon (1880) a landscape generally considered to be among his greatest works. According to Edmund Gosse, Lawson’s newfound popularity had the effect of firing his ambition ‘to an absolute frenzy of excitement’, demonstrated by his intentions for The August Moon, the artist’s attempt to show the colour that could be found in a landscape lit by moonlight. According to his friend, the art critic Heseltine Owen, this was, in Lawson’s eyes, a ‘truth’ that no great painter had yet fully grasped but one he ‘intended to show’.
Lawson’s commitment to his artistry was now taking a heavy toll on his health yet, with an almost fatalistic zeal, he continued to paint, visiting Yorkshire in the autumn of 1880 at the bequest of Henry Mason, an appreciative patron and collector of Lawson’s work. Here, he produced a number of pieces that were exhibited at the Academy and Grosvenor Gallery in 1881 but, after heading south to Devon, the fragile state of Lawson’s health finally forced him to rest.
In December 1881, he left England for the Riviera and, while travelling through Italy, completed his final painting, On The Road to Monaco. Returning to London in the spring of 1882, Lawson was able to attend a private viewing at the Grosvenor Gallery but his health continued to decline and he died in Kensington on June 10th from an acute respiratory infection and pneumonia. As an artist, Lawson only enjoyed widespread popularity for a short time but created a large enough body of work to leave a lasting impression on many of his contemporaries. Joseph Comyns-Carr, a director of the Grosvenor Gallery, which staged Lawson’s memorial exhibition the following winter, commented ‘There was in all his work…the essential secret of beauty in a landscape’ while the art historian Sir JL Caw simply concluded that Lawson was ‘one of the greatest landscape painters’ of the 19th Century.