A gold coin "of the greatest" rarity doubled its already-considerable €50,000 estimate at Germany-based Künker's September 29 numismatic sale.

Formerly of the Siegfried Collection, comprising historic coins for the city of Hamburg, the undated coin weighs 17.53g and is understood to have been produced circa 1668-1673. Künker's lot notes describe it as a "very attractive specimen with fine gold patina."

While this specimen was produced during the reign of King Leopold I, Holy Roman Emperor and King of Germany from 1658-1705 (himself no stranger to the auction block), the origin of this 10 ducat piece actually dates back to the 16^th century.

The 17th century coin is emblazoned with symbols of Hamburg's wealth

Back then, the coins were originally introduced to reflect the wealth of Portugal and its healthy trade with India. It was on these designs that this Hamburg-coined specimen was based. Emblazoned on its front are the city emblem and town castle based explicitly on the Portuguese model.

The coin's reverse is decorated with a Portuguese cross, a design which was later abandoned in favour of the city's coat of arms later in the 17^th century. Also evident are references to Hamburg's banking, trade and commerce, alongside various political events depicted in its design.

In the end, this exceptionally rare 17^th century piece emerged as the favourite in Künker's sale, bringing a remarkable €100,000.

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