A gold coin commemorating the assassination of Julius Caesar, minted just two years after the death of the Romanleader, fetched a record-breaking high bid of $3.5 million at an auction in London.

The gold coin, minted in 46 B.C, bears the image of Marcus Junius Brutus, one of the leaders of Caesar's assassination, as well as the image of two daggers and the words "Eid Mar," which means theIdes of March, a reference to the March 15 date of the killing.

Nearly 100 similar coins minted in silver are known to exist, but the one that sold for $3.5 million in the late October auction is one of only three known to survive that were minted in gold.

The coin was purchased by an anonymous collector, the auction house said.

The auctioneer said the sale marked a new world record for the most expensive coin ever sold.