An 1864 gold 50 lire coin is set to lead the European coin collection of "one of the world's most prolific coin collectors", Ake Linden.
The sale will be held on May 7 in London through A H Baldwin & Sons, which offered Linden's Russian coins in New York in January with great success.
"This extensive and impressive collection of European coinage is part of a calendar of auctions to be held throughout 2014, presenting Ake Linden's large-scale collection to the numismatic market," commented director of world coins at the auction huse, Dimitri Loulakakis.
"Following the success of his Russian coins, which sold through our New York auction earlier this year, in excess of $1m, we fully expect that the European collection will be as popular as its Russian counterpart."
The extremely fine 1865 50 lire coin was struck in Torino under King Vittoria Emanuele II in an incredibly limited mintage of only 103. Described as "by far the rarest one-year type coin of the Italian Kingdom series", it is expected to sell for £50,000-60,000 ($82,718-99,262).
It was the last coin to be minted before the Kingdom of Italy joined the Latin Monetary Union (LMU), which was a union of currencies including France, Belgium and Switzerland - a precursor to the Euro.
Before long, a new standard weight currency was established that could be freely exchanged between the countries, with the Kingdom of Greece and Spain joining in 1868.
Also starring in the sale is the "very rarest of all regular issue coins of modern Greece", the George I gold 100 drachmai, 1876, which was minted in Paris in an issue of just 76 as part of the LMU. It is estimated to sell for an identical sum to the 1865 50 lire coin.
Paul Fraser Collectibles has some exceptional Italian gold coins for sale.