Dublin Castle

King John ordered a castle at Dublin in 1204, some thirty-five years after the Norman invasion of Ireland, commanding that it be built with strong walls and good ditches for the defence of the city, the administration of justice and the protection of the King's treasure. Meiler Fitzhenry, the justiciar, began the work. It became the first administrative centre for the English Crown in Ireland since John's unsuccessful first expedition of 1185, when he had built and issued royal charters from Ardfinnan Castle.

Largely complete by 1230, the castle followed the typical Norman courtyard plan: a central square without a keep, bounded on all sides by tall defensive walls and guarded at each corner by a circular tower. It took the highest point of central Dublin, southeast of the Norman town, and formed one corner of the city's outer perimeter, the River Poddle serving as a natural defence along two of its sides. The city wall ran directly up to the northeast Powder Tower — its calp walls 3.7 metres thick, raised about 1228 over Viking defences that still lie beneath — then swept north and west around Dublin before rejoining the castle at the Bermingham Tower in the southwest.

The Poddle itself was diverted through archways where wall met castle, artificially flooding the moat along the city elevations; one archway and part of that wall survive buried beneath the 18th-century buildings. The whole stood beside the dark pool — Dubh Linn — that gave Dublin its name, and when the walls went up the Liffey was much wider, so that both rivers defended the place.

In January 1592 Red Hugh O'Donnell and the brothers Art and Henry O'Neill broke out of the castle after a period of imprisonment. Once clear of it Henry went his own way and returned safely to Ulster, while O'Donnell and Art, with a guide sent to help them, pushed south for the rural valley of Glenmalure, a rebel stronghold where they knew they would find safety. Art died of exposure on the winter journey, which has been commemorated officially every January since 2009 by the Art O'Neill Challenge, an endurance race and walk.

Visiting in 1620, the English-born judge Luke Gernon was greatly impressed by the wall — "a huge and mighty wall, foursquare, and of incredible thickness".

Through the Middle Ages the wooden buildings inside the castle square were altered and rebuilt repeatedly. The most significant addition was the Great Hall, raised in stone and timber and used in turn as parliament house, court of law and banqueting hall. The Court of Castle Chamber, the Irish counterpart to the English Star Chamber, sat here in a room built specially for it about 1570. Fire damaged the Great Hall in 1673 and it was demolished shortly afterwards.

A second, severe fire in 1684 settled the castle's future. The extensive rebuilding that followed transformed it from a medieval fortress into a Georgian palace, and apart from the Record Tower of about 1228–1230 — the sole surviving tower of the original fortification — no medieval building now stands above ground. Lord Chesterfield built the State Apartments in the 1740s, and the ceiling Vincenzo Valdre painted for St Patrick's Hall around 1790 is composed of three panels: the coronation of George III, Saint Patrick introducing Christianity to Ireland, and Henry II receiving the submission of the Irish chieftains. The result impressed few: the Earl of Arran had already dismissed the place as "the worst castle in the worst situation in Christendom", and the English traveller John Bush, writing in 1764, found the lord lieutenant's residence had "very little of grandeur in its external appearance besides the large square court-yard", though he allowed that some of the rooms were "large and elegant".

General Joseph Holt of the United Irishmen, a participant in the rising of 1798, was held in the Bermingham Tower before his transportation to New South Wales in 1799. In 1907 the Irish Crown Jewels were stolen from the castle; suspicion fell on the Officer of Arms, Sir Arthur Vicars, and rumours about his private life and his London connections are thought to have muddied the investigation. The jewels have never been recovered.

At the very beginning of the Easter Rising of 1916 a force of twenty-five Irish Citizen Army members seized the entrance and guard room before reinforcements reached the castle's small garrison. Through the Anglo-Irish War it was the nerve centre of the British effort against Irish separatism, and on the night of Bloody Sunday in 1920 three Irish Republican Army men — Dick McKee, Conor Clune and Peadar Clancy — were tortured and killed there.

After the signing of the Anglo-Irish Treaty in December 1921 the complex was ceremonially handed over to the newly formed Provisional Government led by Michael Collins. It closed seven centuries in which the castle had been the seat of English and then British government in Ireland — through the Lordship of Ireland (1171–1541), the Kingdom of Ireland (1541–1800) and the United Kingdom (1801–1922) — residence of the Lord Lieutenant, offices of the Chief Secretary for Ireland, and base of a garrison and later of intelligence services.

With the Irish Free State formed in December 1922 the castle ceased to be an administrative seat, and because the Four Courts had been badly damaged in the Civil War it took on the work of the courts for a decade. Douglas Hyde was inaugurated as the first President of Ireland in St Patrick's Hall in 1938, and every president since has taken office in the same room; Erskine Hamilton Childers lay in state there in November 1974, and Éamon de Valera in September 1975.