Scholars are divided over whether this vessel was made as a reliquary or a salt cellar. The marks on the vessel tell us that it was made in London in 1551, probably by the Royal Goldsmith Affabel Partridge, at a time when Catholics in England were being persecuted. He reused an earlier rock crystal cylinder and mounted it in the latest Continental style. The design is similar to the elaborate salt cellars of the period, and the decorative motifs - the masks, strapwork and shells - are secular rather than religious.

In 1737 Lady Mary and Sir Charles Browne, members of a wealthy Catholic family, gave the vessel to the Poor Clare nuns in Rouen, whose foundation had been established in 1644 for English Catholic women in exile. Some years later, the chronicles of the Poor Clares in Rouen record that 'This year 1741 [the vessel] was made into a reliquary to set upon the altar… '.

Lady Browne stated that the vessel had been found 'in the ruins of some old monastery that had been suppressed'. There may be some truth in this romantic vision as many religious artefacts were seized during the Dissolution of the Monasteries (1536-40) and later refashioned. Sir Charles Browne's great-great-grandfather - Anthony Browne, Viscount Montague (1528-92) - was granted monastic lands during the Reformation. Suppose Anthony Browne discovered the crystal tube at this time and had it remade into a prestigious vessel that was passed down through his family.

But was it intended as a reliquary or a salt cellar? Could Affabel Partridge's secular imagery have been simply a foil for the anti-Catholic authorities? There are arguments for and against, but whether or not we discover its complete history, the vessel remains a fascinating piece of craftsmanship highlighting a turbulent part of British history.