The portable altar which is the subject of this paper is preserved in the Musée de Cluny, Paris, catalogued as no. cl. 11.459. 1 It was bought by the Museum on 10 May 1886 at the sale of the Stein Collection. On 25 November 1882, while in the Stein Collection, the altar was drawn by C. Rohault de Fleury who took it to be Italian work of the thirteenth century. 2 He supplied the information that the altar had previously been in the possession of M. Maillet de Boullay and that it was said to have been purchased in Italy. The altar has been cited on a number of occasions and some commentators on the inscription have stated that the text describes the engraved figures; none, however, has attempted a translation or an explanation of which part of the text refers to which part of the engraving, nor has the iconography of the altar been discussed in any detail. 3