The situation chosen by the Norsemen for the first fortress of “Duibhlinn” (A.D. 840) was naturally strong, being on a hill at the junction of the Liffey and the Poddle. After this date we read of several raids upon the dun, or castle of Dublin, including the treacherous entry into the city of Milun DeCogan and Meyler Fitz-Henri during a truce, when all the defenders of the stronghold were put to the sword. This was shortly after the landing of Strongbow. The present area covered by Government buildings includes the ancient site.

When Henry II. came to Dublin a large wooden hall, covered with wattles, was erected in Dame Street, that he might entertain the Irish chiefs who came to pay homage. Upon his return to England he committed “Dublin with its castle and donjon to Hugh de Laci, Fitz-Stephen, and Morice Fitz-Gerald.” Hugh de Lacy became the first Viceroy. It was while he was in England that Meyler Fitz-Henry, who had been appointed Lord Justice in his absence, wrote to King John complaining that he had no safe place to store the King’s treasure, and asking for leave to erect a proper fortress. This he received in the form of a patent dated 1204, which says:—

“But you are first to finish one tower, unless afterwards a castle and palace, and other works that may require greater leisure, may be more conveniently raised, and that we should command you so to do.”

The grant consisted of 300 marks, which was owed to the King by G. Fitz-Robert, and there are no records to show whether FitzHenry ever collected the debt, or even began the castle in the three years afterwards for which he held office. It seems to be a very general opinion that the castle was built about 1220 by Henry Loundres, Archbishop of Dublin, either at his own expense, or that he advanced the money as a loan. A State paper, however, dated 1217, grants the Archbishop two cantreds without Dublin for damage done to his churches in fortifying the castle, and later there are many entries regarding compensation to be paid in money to Henry Loundres in lieu of land which had been encroached upon when extending the fortifications.

In 1242 an entry records that the windows of St. Edward’s Chapel belonging to the castle were to be glazed, and divine service held. This building seems to have been outside the fortress walls, on the site of the present Chapel Royal which was erected in 1814. In 1243 a hall was to be built 120 feet long and 80 feet wide. It was to have glazed windows, with a round one at the gable end 30 feet in diameter.

The entrance to the castle was by a drawbridge on the north side, the site now being occupied by the gate to the Upper Castle Yard. This bridge was flanked by two towers, and defended by a portcullis, and later by ordnance as well. From the gate towers, often used as State prisons, a high curtain or wall extended east and west. In the westward direction it joined what in later years was known as Cork Tower, because it was rebuilt by the great Earl of Cork in 1629, it having fallen in 1624, and been only partly restored. He spent £408 on it.

From this the wall was continued south to the Birmingham Tower, which is said to have derived its name from its having been erected either by John Birmingham, Earl of Louth, Lord Justice 1321, or Walter Birmingham, who held office in 1348. It is more likely, however, that this tower is identical with that known as the high tower, and that it received the name Birmingham after William Birmingham and his son Walter had been imprisoned there in 1331, otherwise the fortress would have been incomplete prior to 1321, and the side with least natural defence unprotected. From Birmingham Tower the curtain extended eastward (intersected by two smaller towers) to Wardrobe Tower. From this the wall was continued northward to the Store Tower near Dame’s Gate, which was in its turn connected with the eastern gate tower. There were two sallyports in the wall.

Of the eight towers which once protected the fortress only the Wardrobe Tower now remains, often erroneously called Birmingham Tower. This, as its name implies, is where the royal robe, cap of maintenance, and other furniture of state were kept. The sword of state is still preserved there, and also the records which were removed from Birmingham Tower. The lower portion is the original masonry, but an upper storey was added when the Chapel Royal was built. The Birmingham Tower was rendered unsafe by an explosion of gunpowder in Ship Street and had to be taken down. A lighter structure was erected on the site, which contains the present kitchen and viceregal supper-room. The other towers were gradually removed to make room for new buildings.

The Anglo-Irish used to decorate the gate and walls of the castle with the heads of the slain, and in 1316 some four hundred heads were sent from Wicklow for this purpose.

The castle did not become a permanent residence of the Viceroy until 1560 by order of Elizabeth, and in 1565 Henry Sydney took up his abode in it. He also enlarged and beautified it, and placed the State papers there in safe keeping.

The castle has stood several successful sieges. In 1478 Gerald, 8th Earl of Kildare, was superseded as Lord Deputy by Lord Grey of Codnor. He refused to resign, and Keating, Prior of Kilmainham, and Constable of the Castle, sided with him, and fortified the stronghold against the new Deputy. He destroyed the drawbridge, and Lord Grey, finding his numbers too small to force an entrance, returned to England, and Kildare was shortly afterwards reinstated.

Again, in 1534, young Lord Offaly, known as “Silken Thomas” from the splendour of his horses’ trappings, hearing a false report that his father had been treacherously executed in England, returned the Sword of State to the Council, which he held as Deputy in the Earl of Kildare’s absence, and commenced hostilities against the castle.

It is said the citizens readily admitted him within the walls of Dublin. His chief attack was from Ship Street, but the Constable of the castle getting the thatched houses there set on fire, the besiegers fell back into Thomas Street.

Lord Offaly having been obliged to commence hostilities against Ossary, the siege was not carried on with much heart. Many of the arrows sent into the castle were headless, and others bore letters saying some of the besiegers were really in sympathy with the King’s party.

Upon the rumour of help from England, the citizens closed the gates and made prisoners of the attackers.

Lord Thomas hurried back, and at once laid siege to the city itself, but his force was too small to have any effect.

As he had seized the Dublin children who had been sent to outlying villages on account of the plague, the citizens agreed to liberate his party if the little ones were restored. This was done, and shortly afterwards aid from England quelled the rebellion.

Several exciting escapes have been made by prisoners from the castle. In 1587 Hugh O’Donnell was confined in one of the gate towers for three years, when he and a companion managed to escape on to the drawbridge by a rope. He was, however, treacherously sent back to Dublin by O’Toole of Castlekevin, upon whose hospitality he had thrown himself. At this time a partly dry and partly wet moat surrounded Dublin Castle, and O’Donnell was now imprisoned in the Wardrobe Tower round which the Poddle flowed. He, however, escaped again the next year through the water, and, arriving after much hardship at Glenmalure, eventually reached the North in safety.

In 1697 Lord Delvin was imprisoned in one of the gate towers for taking part in a conspiracy against the King. The Lord Deputy hearing that he meditated escape, desired Tristram Ecclesten, Constable of the Castle, to remove his prisoner from the upper to a lower storey. Not only did Ecclesten neglect to do this, but he allowed Lord Delvin to have visitors, who managed to convey him a rope, by which he escaped. Next year he surrendered himself and was pardoned.

Law Courts and Parliaments have at different times been held in the castle.

In 1689 King James made a State entry, and stayed one night there after the battle of the Boyne.

In 1783 St. Patrick’s Hall was built. In 1784 the Viceregal Lodge was bought, and since then the State apartments of the castle have only been used during the Dublin season.