LONDON — A masterwork by John Constable, R.A. (1776–1837), the full-scale six-foot sketch for “View on the Stour near Dedham,” circa 1821–22, will be offered alongside other masterpieces by Reynolds, Leighton, Lowry, Spencer, Bacon and Freud in Christie’s 250th anniversary Defining British Art sale in London Thursday, June 30.

The work (estimate upon request), the last great 6-foot sketch in private hands, illustrates why Constable was considered the father of British Modernism and why the French painters, particularly the Impressionists, revered Constable as an instinctive painter of nature and the elements.

Jussi Pylkkänen, Global President of Christie’s International: “Not since Constable’s ‘Lock’ have we had the opportunity to work with a painting of this calibre by one of the titans of British painting. To stand in front of this expansive work, is to understand why the great British modern painters and even the French Impressionists revered Constable as their spiritual mentor. Constable famously said that “Painting is but another word for feeling” and later that “I do not consider myself at work unless I am before a 6-foot canvas.”

Visitors to Christie’s in June will be able to see a rarely exhibited masterpiece by Constable that describes his passion for paint and his ability to paint dramatic landscapes on the grand scale. “It is fitting that Christie’s should be given the opportunity to sell this masterpiece in our Defining British Art sale which marks the 250th anniversary of the founding of this great institution,” he said.

John Stainton, International Director and Head of British Old Master Paintings at Christie’s, added, “In his celebrated series of full-scale sketches Constable gave full rein to his artistic expression, freed from the necessity to work on a high level of ‘finish’ in the manner contemporary taste demanded.”

Christies is at 8 King Street. For more information, www.Christies.com or 44 (0)20 7839 9060.