The third son of Philip Hermogenes Calderon, W.F. Calderon studied at the Slade unde Legros and founded the School of Animal Painting in 1894, running it until 1916. Animals featured prominently in his work, even when his subjects were literary, and no doubt the attraction of the present onw was the opportunity it offered to introduce horses and donkeys. It occurs in the Morte d'Arthur, Book 6, ch.3. The four queens in question - Morgan le Fay, Queen of the land of Gore, the Queen of Northgalis, the Queen of Eastland and the Queen of the Out Isles - accompanied by four knights, discover Lancelot asleep under an apple tree. Each wants him for her paramount, so Morgan le Fay lays him under enchantment and has him carried to her castle where he is asked to choose one of them. Faithful to Queen Guinever, he refuses, and eventually makes his escape.

The picture was exhibited at the Royal Academy in 1908, when such subjects were rapidly going out of fashion. The notice it received in the Athenaeum, though not unappreciative of its merits, contains a telling element of amused contempt. 'Mr Frank Calderon's 'How four Queens found Sir Lancelot sleeping' is commonplace in execution, but informed by a touch of real fancy. The artist had a vivid first idea, and the huddled group of ladies on white donkeys is pretty and full of childish romance.' Curiously enough, of all the Arthurian subjects, this one retained its appeal longer than most among artists of the old persuasion, and even had a minor revival within the modern movement. Frank Cadogan Cowper, 'the last of the Pre-Raphaelites', exhibited a version at the Royal Academy at the incredibly late date of 1954 (see The Last Romantics, exh. Barbican Art Gallery, 1989, no.161, repr. in cat.) Meanwhile in 1941 the theme had been treated in a watercolour by David Jones (Tate Gallery).