Picturesque is an aesthetic ideal introduced into English cultural debate in 1782 by William Gilpin in Observations on the River Wye, and Several Parts of South Wales, etc. Relative Chiefly to Picturesque Beauty; made in the Summer of the Year 1770, a practical book which instructed England's leisured travelers to examine "the face of a country by the rules of picturesque beauty". Picturesque, along with the aesthetic and cultural strands of Gothic and Celticism, was a part of the emerging Romantic sensibility of the 18th century.
The term "picturesque" needs to be understood in relationship to two other aesthetic ideals: the beautiful and the sublime. By the last third of the 18th century, Enlightenment rationalist ideas about aestheticism were being challenged by looking at the experiences of beauty and sublimity as being non-rational (instinctual). Aesthetic experience was not just a rational decision - one did not look at a pleasing curved form and decide it was beautiful - rather it was a matter of basic human instinct and came naturally. Edmund Burke in his 1757 Philosophical Enquiry into the Origin of Our Ideas of the Sublime and the Beautiful said the soft gentle curves appealed, he thought, to the male sexual desire, while the sublime horrors appealed to our desires for self-preservation. Picturesque arose as a mediator between the opposed ideals of beauty and the sublime, showing the possibilities that existed in between these two rationally idealized states. As Thomas Gray wrote in 1765 of the Scottish Highlands "The mountains are ecstatic.. None but.. God know how to join so much beauty with so much horror." See also Gilpin and the picturesque.
The pictorial genre called ‘Picturesque’ appeared in the 17th century and flourished in the 18th. As well as portraying beauty in the classical manner, eighteenth-century artists could overdo it from top to bottom. Their romantic sensitivity could aspire to the sublime or be pleased with the picturesque. According to Christopher Hussey, “While the outstanding qualities of the sublime were vastness and obscurity, and those of the beautiful smoothness and gentleness, the characteristics of the picturesque were “roughness and sudden variation joined to irregularity” of form, colour, lighting, and even sound.”  The first option is the harmonic and classical; the second, the grandiose and terrifying; and the third, the rustic. This triple definition by Hussey, although modern, is true to the concept of the epoch, as Uvedale Price explained in 1794. The examples Price gave of these three aesthetic tendencies were Haendel as the sublime, a pastorale by Corelli as the beautiful, and a painting of a Dutch landscape as the picturesque.
During the mid 18th century the idea of purely scenic pleasure touring began to take hold among the English leisured class. Gilpin's work was a direct challenge to the ideology of the well established Grand Tour, showing how an exploration of rural Britain could compete with classically oriented tours of the Continent. The irregular, anti-classical, ruins became sought after sights.
Picturesque-hunters began crowding the Lake District to make sketches using 'Claude Glasses' - tinted portable mirrors to frame and darken the view, and named after the 17th century landscape painter Claude Lorrain, whose work Gilpin saw as synonymous with the picturesque and worthy of emulation. As Malcolm Andrews remarks, there is "something of the big-game hunter in these tourists, boasting of their encounters with savage landscapes, "capturing" wild scenes, and "fixing" them as pictorial trophies in order to sell them or hang them up in frames on their drawing room walls". Gilpin himself asked, "shall we suppose it a greater pleasure to the sportsman to pursue a trivial animal, than it is to the man of taste to pursue the beauties of nature?" After 1815 when Europe was available to travel again after the wars, new fields for picturesque-hunters opened up in Italy. Anna James wrote in 1820 "Had I never visited Italy, I think I should never have understood the word picturesque". Henry James exclaimed in Albano in the 1870s "I have talked of the picturesque all my life; now at last.. I see it".
Picturesque meaning literally "in the manner of a picture; fit to be made into a picture" was a word used as early as 1703 (Oxford English Dictionary), and derived from an Italian term pittoresco, meaning, "in the manner of a painter," William Gilpin's Essay on Prints (1768) defined picturesque as " ... a term expressive of that peculiar kind of beauty, which is agreeable in a picture" (xii).
- William Combe and Thomas Rowlandson published an 1809 poem with pictures called The Tour of Doctor Syntax in Search of the Picturesque which was a satire of the ideal and famously skewered Picturesque-hunters.
- William Gilpin, Three Essays: On Picturesque Beauty; On Picturesque Travel; and on Sketching Landscape: to which is Added a Poem, On Landscape Painting was published in London, 1792.
- Christopher Hussey, The Picturesque: Studies in a Point of View, 1927 focused modern thinking on the development of this approach. The picturesque idea continues to have a profound influence on garden design and planting design.
- Richard Payne Knight, An Analytical Inquiry into the Principles of Taste, soon followed, and went into several editions that the author revised and expanded.
- Uvedale Price, An Essay on the Picturesque, as Compared with the Sublime and the Beautiful; and on the Use of Studying Pictures, for the Purpose of Improving Real Landscape, revised. edition London, 1796.
- Humphry Repton applied picturesque theory to the practice of landscape design. In conjunction with the work of Price and Knight, this led to the 'picturesque theory' that designed landscapes should be composed like landscape paintings with a foreground, a middle ground and a background. Repton believed that the foreground should be the realm of art (with formal geometry and ornamental planting), that the middleground should have a parkland character of the type created by Lancelot "Capability" Brown and that the background should have a wild and 'natural' character.
- John Ruskin identified the "picturesque" as a genuinely modern aesthetic category, in The Seven Lamps of Architecture.
- Dorothy Wordsworth wrote Recollections of a Tour Made in Scotland, A. D. 1803 (1874) considered a classic of picturesque travel writing.
- James Buzard (2001). "The Grand Tour and after (1660-1840)". In The Cambridge Companion to Travel Writing.
- Hussey, Christopher. The picturesque: studies in a point of view (1927), G.P. Putnam's Sons, London and New York.[page needed]
- Glenn Hooper (2001). "The Isles/Ireland". In The Cambridge Companion to Travel Writing.
- Malcolm Andrews (1989). "The Search for the Picturesque", p.67.
- John Macarthur The Picturesque: architecture, disgust and other irregularities
- George P. Landow, "Ruskin on the Picturesque"
- "Turner's journeys of the imagination"
- Landscape Style of Repton, Price and Knight
- Pictures and Poetry. Debunking the Bunk: An Examination of Picturesque Influence, by Keith Waddington. A Masters Thesis at Concordia University.