One of the four surviving original copies of Magna Carta of 1215 was until recently housed highly inappropriately in the cloister gift shop of Salisbury Cathedral. A limited competition was held in 2000 to design a dedicated gallery, on a sensitive southern site, to show the manuscript with interpretative materials and facilities for visitors. The competition initially attracted over 80 entries and Marshall was included in an impressive final short list that included Daniel Libeskind and David Chipperfield. But the cathedral authorities failed to agree on a winning design and abandoned the competition.

The Marshall proposal was probably the most radical and yet simple in concept. Underground visitor facilities were to be created beneath a ‘lake’ of reflective glass. This ensured that the famous views of the cathedral were uninterrupted. A small pavilion was proposed to house Magna Carta and the grassy ramped access implied a sense of the green spaces of Runnymede.