The relief is a fragment from a larger piece and as such there are losses to the left side. Otherwise the condition is good, with minor dirt and wear to the surface consistent with age. There are a few further minor losses and chips, including to the bottom left corner of the trefoil arch. There is naturally occurring, light brown mottling to the black marble throughout. There are minor nicks and abrasions to the surface throughout. There is particular dust in the crevices of the carving. There are two holes to the back at the top, which are filled with cement and metal struts. There are also remnants of a paper label, as well as some rust-coloured staining, to the back. There is minor general wear to the velvet covered base.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

This beautiful and intriguing relief fragment is made of Belgian Black, or Tournai marble. This black limestone, quarried from the banks of the River Scheldt, was mostly carved in Tournai, and of particular popularity for the creation of tombs, altars, and baptismal fonts. See, for a well-known example, the large, square baptismal font with scenes from the Life of Saint Nicholas, dating to the 12th century, in Winchester Cathedral.  Depicting Saint John the Evangelist, under a trefoil niche and with identifying inscription in Gothic Script, the present relief fits well within the corpus of Tournai marble monumental and funerary sculpture of the 15th century - see, for instance, a memorial panel for Gauthier de Beauvoir, depicting a Crucifixion, with elaborate inscripiton, from the former Cathedral of Our Lady of Cambrai (Nys 2001, op. cit., fig 22, no. 10). For saints in individual niches, compare to the slightly earlier Tournai marble memorial panel for Brice li Rois (ibid., no. VI) and the Tournai Cathedral 'new porch' (Van de Walle, op. cit., no. 116-117). Further comparison for compositions with individual saints can be found in rood screens dating to the end of the 15th century, including that of Saint Peter's Church in Louvain (Steppe, op. cit., fig. 18). The present relief is therefore likely to have been part of a memorial or a rood screen. The mark at the top of the relief, however, is enigmatic. Since many of the memorials for individual families in the Tournai region feature complicated identifying features and coats of arms, it can only be assumed that this intriguing sign had a similar function. 

RELATED LITERATURE
J. Steppe, Het Koordoksaal in de Nederlanden, Brussel, 1952; A. L. J. Van de Walle, Belgique Gothique, Architecture, Art Monumental, Brussels, 1971; L. Nys, La pierre de Tounai, Son exploitation et son usage aux XIIIème et XIVème et XVème siècles, Tournai and Louvain, 1993; L. Nys, Les tableaux votifs tournaisiens en pierre, 1350-1475, 2001