A Bohemian 'Master of Koula' portrait beaker with the Siege of Vienna Riesengebirge, circa 1685

the thick-walled flared form engraved on one side in tiefschnitt with a portrait of the Elector Johann Georg III of Saxony in profile to sinister wearing armour, a sword over his shoulder, within a ribbon-tied wreath inscribed CURFÜRST ZU SACHSEN JOHAN GEORG DER III, the reverse with a view of  a besieged city within an extended oval line panel surmounted by a cherub's head with outstretched wings and flanked by cornucopiæ, the lower section cut with thumbnail flutes 

Helfried Krug Collection, Baden-Baden, his sale, Sotheby's London, 7th July 1981, lot 156

Brigitte Klesse, Glassammlung Helfried Krug, Vol. 1, no.179
Dietmar Zoedler, Schlesisches Glas - Schlesische Gläser, p.80, pl.30

Generally in good condition
"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."

Elector Johann Georg of Saxony was one of the heroes of the Siege of Vienna against the Turks in 1683, and died of the plague in 1691.

Compare with the Koula-beaker in the Decorative Arts Museum, Prague (Inv.no.30.720/1849)