This design is the fourth of four cartoons designed and made for the window of a landing in Burne-Jones' house in Rottingdean, Sussex. The windows (now in the V&A: C.623 to 626-1920) encapsulate the story of the Quest for the Sangreal (Holy Grail).
This cartoon depicts the Holy Grail on an altar beneath an architectural canopy, guarded by three angels. Below the inscription reads: "HOW THE SANGREAL ABIDETH IN A FAR COUNTRY WHICH IS SARRAS THE CITY OF THE SPIRIT"