A US 1833 half eagle has sold for $1.3m in an auction jointly held by Stack's Bowers and Sotheby's.
The lot led the fourth instalment of the D Brent Collection sale, beating its estimate of $950,000 by 42.1%.
The coin has long been an object of desire for numismatists, having once been the centrepiece of King Farouk of Egypt's legendary collection.
The auction house comments: "If the half eagles of the Pogue Collection were to be evaluated on no other basis but their beauty and proximity to perfection, the dozens of landmark examples of this denomination found in this collection would need to find their place in line behind this one…
"Rarity and preservation coalesce at their highest levels around this coin.
"PCGS has certified only two Proof half eagles of this entire design type, the other being an 1832 in Proof-64, and the only other privately owned Proof of this date has been lightly circulated."
Pogue focuses on the first century of the US Mint and has assembled one of the finest US collections in history.
He began selling it off last year, a decision he explained to Forbes Magazine: "In my mind the collection is complete.
"Some of these coins have been off the market for 35 or 40 years. It's time to share them with the numismatic community."
The collection is expected to bring in $200m in all, with two more auctions to be held later this year.
Previous sales included a $2.3m record for a US quarter eagle and a Lord St Oswald 1794 Flowing Hair silver dollar that made $5m.
Click here to check out our amazing range of coins.
Please sign up to our free newsletter to receive exciting news about coin and banknote auctions.