The Irish Crown Jewel Hiest was the 1907 theft of the ceremonial jewels of the Order of St. Patrick from Dublin Castle, a major unsolved scandal involving Sir Arther Vicars (Ulster King of Arms) and potential inside job suspects like Francis Shackleton, with the valuable emerald- and diamond-encrusted regalia never recovered and sparking political intrigue between nationalist and unionist factions.
Irish Mythology - Mythical Cycle - Book of Invasions