With so few clues, how was 'Henry the bishop' identified? Quite simply, by a process of elimination. When the plaques came to The British Museum in 1852, Augustus Wollaston Franks deduced that Henry of Blois, bishop of Winchester (1129 - 71) was the only eligible English monk-bishop with the appropriate date, status and political interest.
When they arrived in the Museum, the plaques were joined together, and had been previously sold as an alms dish. However, it was clear that this was not their original state. What sort of object did the plaques decorate? The clue probably lies in the hands of Henry, as it was customary practice for a donor to be represented holding an image of the gift he was making. He is depicted carrying two objects - a crozier (a bishop's staff) and another, more mysterious, rectangular object, decorated with enamelled, turquoise discs. It most likely represents an altar. Such altars were richly decorated, encrusted with rare stones and inlaid with exotic marbles. Alternatively, these plaques may have been attached to a cross set on the altar.