A letter from Padraig Pearse penned hours before his death is expected to reach up to €100,000 at auction today.
The poignant missive giving instructions for his possessions is among more than 600 items from the War of Independence era on sale in Dublin.
Also going under the hammer at the James Adam salerooms on St Stephen's Green are a batch of 14 letters on Michael Collins' love life.
The insight into the revolutionary leader's intimate affairs has sparked a small media stir and could reach €20,000.
Other highlights include an extremely rare original Blueshirt said to be of enormous historical importance.
The shirt, a military-style tunic from the 1930s, is embroidered with "Fine Gael" above the breast pocket and has a red cross badge over the shoulder.
The party has remained tight-lipped on whether it plans to bid for the shirt which was owned by John Prendergast from Oulart, Co Wexford who died aged 22 in 1938.
Members of the Army Comrades Association, popularly known as Blueshirts, earned an ambiguous reputation.
The association was founded in the early 1930s to defend free speech against IRA attacks on Cumann na nGaedheal meetings, but was linked to fascist movements across Europe at the time.
Many members went to fight in the Spanish civil war in 1936 on the side of Franco's nationalists. It is not known how Mr Prendergast died.
Rebel flags dating from the time of the Easter Rising and detailed correspondence between Charles Stewart Parnell and African pioneer Cecil Rhodes, who states his support for Home Rule, also go under the hammer.
A match day ticket for the Tipperary-Dublin clash in Croke Park on Bloody Sunday, November 21, 1920, is also up for grabs in the sale jointly organised by Mealy's Auctioneers.
Another ticket from the game, albeit in better condition, was sold for €7,500 three weeks ago - this one has a guide price of around €3,000.
A similar auction last year coinciding with the 90th anniversary of the Easter Rising saw the first draft of Ireland's national anthem sold for more than €250,000, contributing to a sale total of €3.5m.