See the copy of the 1916 proclamation Enlarge Image

Hastily printed in Dublin on Easter Sunday morning on 23 April 1916, it is thought there are only about 20 original proclamations still remaining.

After being kept locked away in a drawer for many years, this copy is expected to reach between �70,000 and �100,000 when it goes under the hammer in Dublin next month as part of the annual Important Irish Art Sale.

Stuart Cole of auction house Adam's and Sons says it was brought in by someone whose father had picked it up on Easter Sunday in 1916.

"He folded it up, put it in an envelope and it sat there until about May this year, when his grandchildren came in and said they thought it might be an original proclamation," he says.

Only 1,000 copies were printed because of First World War paper shortages, and the irregular type styles and ink smudging mean that no two copies are the same.

This copy was authenticated as original by the National Library of Ireland, as proclamations were reprinted in 1922 for veterans of the Rising and the Irish War of Independence.

Business, by Jack B Yeats, is being auctioned

Mr Cole says bids could be expected from both institutions and "private people with a sense of history and the importance of this document".

"There are a couple of famous names who are known to be collecting Irish historical documents," he says.

One name rumoured to be interested is wealthy former Riverdance star Michael Flatley.

"His name pops up an awful lot but he does have an interest in Irish historical documents and books - he's furnishing his house down in County Cork, so you never know."

A substantial collection of Irish art is also being auctioned, and potential buyers from Northern Ireland have had a chance to view the pieces at a bank in Belfast.

Auctioneer Stuart Cole with the 1916 Proclamation

Many of the items are part of the Jefferson Smurfit collection, after the paper and packaging firm was taken over by an American venture capital firm.

Mr Cole says it includes significant works by "blue chip artists" such as Roderic O'Conor's Nude with Stove and Jack B Yeats' Business, which could both reach up to �200,000.

However, those with shallower pockets are also being encouraged to invest, and there is "something for the first-time buyer", according to Donal Delahunt, Head of Private Banking at First Trust.

"It's a long-term investment, but you also get the benefit of enjoying the art," he says.

"Traditionally people invested in pensions and equities or property, but this is an alternative.

"Who knows, in 20 years time, it could be worth much more."

And with the 100th anniversary of the Easter Rising just 12 years away, the proclamation could be a shrewd investment for someone with a bit more cash.