A club formed in 1688 by the leading Whigs of the day, and held in Shire Lane (now Lower Serle's Place) in the house of Christopher Cat, a pastry-cook, who supplied the mutton pies, and after whom the club was named Sir Godfrey Kneller painted forty two portraits of the club members for Jacob Tonson, the secretary, whose villa was at Barn Elms, and where latterly the club was held. In order to accommodate the paintings to the height of the club-room, he was obliged to make them three-quarter lengths, hence a three-quarter portrait is still called a kit-cat. Strictly speaking, a kit-cat canvas is twenty-eight inches by thirty-six.
“Steele, Addison, Congreve, Garth, Vanbrugh, Manwaring, Stepney, Walpole, and Pulteney were of it; so was Lord Dorset and the present Duke. Manwaring ... was the ruling man in all conversation ... Lord Stanhope and the Earl of Essex were also members ... Each member gave his [picture].” —Pope to Spence
Cowley the poet lived at Barn Elms Villas.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894