A fine Ayyubid or early Mamluk marvered glass bottle, Egypt or Syria, 12th/13th century

of translucent dark brown blown glass, of ovoid form, tapering to a thin neck with everted rim, decorated throughout with irregular zigzags in opaque white that becomes pale blue at the edges

Very good overall condition, intact, minor abrasions and scuffs, as viewed.
"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 elegant vessel is typical of the marvered glass production which reached its artistic peak during the Ayyubid and early Mamluk periods (12th-14th centuries).  The origins of marvered glass stretch back further, however, as glass of this type was in production from the early Islamic period, inspired by late Roman models (see Carboni & Whitehouse 2001, p.106).

Marvering is a versatlie technique of embellishing glass whereby a continuous spiralled trail of hot (and therefore malleable) glass is applied to a dark base that is generally either purple, blue or green.  This particular bottle appears to belong to a group which demonstrates a less controlled and regular marvered pattern than other known examples, which Carboni argues (in his discussion of kohl bottles) might indicate a final stage in the production of this type of marvered container.

A bottle of similar marvered design is in the Al-Sabah Collection, Kuwait (Carboni 2001, p.304, cat.80a-b).