Possible Clues:

• Christ's cup at the Last Supper, sought by medieval knights
• Legendary chalice
• Entirely sound, good bar that is object of quest
• Sought-after object in medieval tales (and the 1993 theme of the 39-Across)
• Cup at the Last Supper
• Object of quest -- go high with Hillary
• Something most eagerly sought or pursued — lily or hag (anag)
• Roman address covers fantastic glory in much sought after cup
• Platter used at the Last Supper
• Object of search for lost glory in winter fall