An Irish gold pistole coin issued by the Duke of Ormonde in the 17th century will cross the block at Dix Noonan Webb on September 15.
It's valued at £80,000-100,000 ($123,070-153,815).
The lot forms part of the collection of Theo Bullmore, a numismatist and managing director at financial services house KPMG.
The duke (1610-1688), who served as lord lieutenant of Ireland, issued the coins during the Great Rebellion of 1642-1649.
The emergency currency was used to pay British troops garrisoned at Dublin, who brutally put down the rebels.
Will Bennett of Dix Noonan Webb told the Irish Post: "This is one of the great rarities of Irish coinage.
"This example is only of two known Ormonde pistoles which are available to the market.
"It also recalls a turbulent time in the country's history when the authorities found themselves short of currency and had to resort to unorthodox methods to find a solution."
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