During the long vacation of 1857 Rossetti went up to Oxford with Morris on a visit to the architect, Benjamin Woodward, who was at work upon a debating hall for the Union Society, and seeing an opportunity for mural decoration of a kind never previously attempted in England in the new hall of the Union, he became fired with an idea for carrying it out. The hall was a long building, with an apse at each end, and a gallery running all the way round. In this gallery were bookcases, and above the cases were ten semi-circular bays, each pierced with a pair of circular windows. These bays, it was suggested, should be painted with scenes from the Arthurian legend, and the roof, as part of the general scheme, was to be decorated in a harmonious manner. A building committee was in charge of the operations, and without any clear idea of its responsibilities or restrictions it fell in with Rossetti's proposal that he and a select band of artists should execute the work gratuitously, but that the Union should defray their expenses at Oxford and should provide all necessary materials. The time estimated for completing the work was six weeks. Seven artists, including Rossetti, Burne-Jones, and Morris, were enlisted without much trouble, the remaining four being Arthur Hughes, Spencer Stanhope, Val Prinsep, and J. Hungerford Pollen, who had already won much credit from his painting of the roof in Merton College Chapel. Rossetti took as subjects for two bays _Launcelot asleep before the Chapel of the Sanc Grael_ and _Sir Galahad, Sir Bors and Sir Percival receiving the Sanc Grael_. The others chose similar themes, but in a short time it was found that the work in hand was considerably more than had been anticipated, though abundant evidence remains of the enthusiasm which was put into it. Unfortunately the delight was not to be of long duration. Almost before the pictures were finished they had begun to decay, the effect of tempera laid direct upon a new brick wall, with no preparation but a layer of whitewash, being quite inadequate to resist the English climate. Several of the designs were never completed. In 1859 some arrangement was entered into by the Union with a Mr. Riviere to fill the three blank compartments; and after that the ill-fated undertaking, on which so much pains and so much skill had been spent, gradually faded away and resolved itself into what it is to-day, a dingy blur of colours in which may be distinguished the occasional vague form of an armoured limb or a patch of flowery background.