A rare original copy of the 1916 Proclamation has been sold at a Dublin auction to a mystery U.S. buyer.

Lot 184, a 30-inch by 20-inch piece of Irish history, had collectors on the edge of their seats when it flashed on a big screen at the Whyte’s auction in the lower ground floor of the Freemason’s Hall in Molesworth Street, close to the seat of government in Leinster House.

It is believed to be one of just 50 of the original 1,000 copies printed in Liberty Hall and published on April 24, 1916, by the Irish Volunteers and Irish Citizen Army.

Most of the copies were destroyed during the Easter Rising, the 100th anniversary of which is being officially marked this month. The seven signatories of the document famously fought for liberation from British rule.

Read more 1916 Easter Rising centenary stories

The war to claim this document was between bidders in Ireland and the U.S.

Auctioneer Ian Whyte was patriotically dressed in green socks, white shirt and orange tie as he raised his gavel for what he called “one of the most important lots in the auction.”

Bidding opened at €120,000 and Whyte told his audience, “We sold this 15 years ago to a collector who has now decided to part with this fantastic collection.”

Two anonymous phone bidders battled it out for the treasure, which finally went to a U.S. buyer for €185,000.

Other memorials sold at the auction included Rosary beads given to a British Army lieutenant by a mother whose son was arrested after the Rising, a gold Cuman na mBan badge like the one worn by Countess Markievicz, and a 100-year-old bottle of Irish whiskey. It was casked in 1916 and bottled in 1966 and fetched €15,000.

An Easter Monday, 1916, race card from Fairyhouse expected to go for between €300 and €500 fetched a surprising €4,000.

Original copy of the 1916 Proclamation: One hundred years after the Easter Rising historic items go up for sale in the apt location of the Gresham Hotel.