[2] The seal was affixed to documents issued by the Privy Council of Ireland and its head the chief governor (latterly called the Lord Lieutenant).

[4] In the fourteenth century, the Chancellor was entitled to a guard of six men-at-arms and twelve mounted archers, in part to protect the seal in his custody.

[6] If the Lord Chancellor was unable for whatever reason to transact business, the Crown might designate another senior judge to act in his place without the Great Seal.

[30] In 1417, the Chancellor, Laurence Merbury, refused to authenticate with the seal a petition to the King from the Parliament on the state of Ireland.

[10] In July 1442, chancellor Richard Wogan fled Ireland after being accused of crimes, including stealing the Great Seal, which was soon handed over to Thomas Nortoun of St Saviour's Priory, Dublin by a person whom Nortoun refused to name to the Privy Council, citing the seal of confession.

[34][35][36] The Lord Deputy Gerald FitzGerald, 8th Earl of Kildare refused Edward IV's command to annul this, and it was not until Poynings' Parliament in 1495 that this was done.

[36][37] In 1478, after Kildare was replaced as Lord Deputy by Henry Grey, 4th (7th) Baron Grey of Codnor, the Lord Chancellor Rowland FitzEustace, 1st Baron Portlester, who was Kildare's father-in-law, organised a campaign of non-co-operation with the new Deputy and refused to hand over the Great Seal, making the conduct of official business impossible.

[10] King Edward IV ordered Thomas Archbold, the Master of the Royal Mint in Ireland, to strike a new Great Seal, "as near as he could to the pattern and fabric of the other, with the difference of a rose in every part".

[39][40] In 1484, clerk James Collynge was charged with forging the Great Seal of Ireland for a fake pardon to the treasurer of Limerick Cathedral, and outlawed unless he appeared before the Chief Justice of the Common Pleas.

[44] The 1722 patent for Wood's halfpence was issued under the British seal rather than the Irish, which was among the complaints Jonathan Swift made in his Drapier's Letters condemning the currency.

Napper Tandy of the Society of United Irishmen challenged his 1792 arrest on the grounds that government officials, from the Lord Lieutenant down, had been appointed under the British rather than the Irish seal.

On the reverse is the Queen on horseback, the horse fully caparisoned, with a plume of ostrich feathers floating from the headstall, led by a page bare-headed.

[61][62] According to Hilary Jenkinson, "a fairly intensive search some years [before 1954] in England and Ireland for impressions of the Irish Seals produced a total of only forty, for the period from the thirteenth century [to 1800]".

On 12 February, Robert Peel, the Home Secretary, sent the seal to Marquess Wellesley, the Lord Lieutenant, with a covering letter.

[69] The 1902 seal of Edward VII, which passed to Redmond Barry on the king's demise, was sold at auction in 1969 for £750,[70] and is now in the National Museum of Ireland.

[72][73] The physical seal was in the Crown and Hanaper Office in the Four Courts when that was occupied by the Irish Republican Army on 14 April 1922 in the buildup to the Civil War.

[77] The Great Seal of Ireland became obsolete on 6 December 1922, with the coming into force of the Constitution of the Irish Free State.

[72] Under the Irish Free State (Consequential Provisions) Act 1922 a separate Great Seal of Northern Ireland was created.

[72] However, when the Free State came into being on 6 December 1922, Gerald Horan, outgoing Clerk of the Crown and Hanaper, informed Hugh Kennedy, the incoming Attorney General of Ireland, that "he had handed over the Great Seal of Ireland to the 'Imperial Representative' [i.e. Governor-General Tim Healy] at the Viceregal Lodge but was retaining the 'former' Great Seal".