In the fourth volume of John Constable's Correspondence the focus shifts to the artist's broader professional relationships, bringing together letters exchanged with patrons, art dealers, and fellow artists. These documents illuminate the mechanisms of patronage, the commercial realities of the art world, and Constable's efforts to establish and maintain his reputation. The volume also highlights a period of profound transition in artistic culture, as traditional aristocratic patronage gradually gave way to an increasingly commercialised marketplace centred on exhibitions, dealers, and private collectors. Through Constable's dealings with influential patrons, his negotiations with English and French dealers, and his interactions with contemporaries within the Royal Academy and beyond, the correspondence reveals both the opportunities and the anxieties generated by these changing conditions. Edited with an introduction and notes by R.B. Beckett.