State Apartments (Dublin Castle)

The State Apartments in Dublin Castle, Republic of Ireland, are an extensive suite of rooms formerly used by the Lord Lieutenant of Ireland for personal accommodation and public entertaining during the Castle Season (January to 17 March - St. Patrick's Day), and largely date from the era of British rule in Ireland. Visiting members of the British Royal Family also stayed there. Located in the southern range of buildings of the Upper Yard of the Castle, today these richly decorated rooms are used by the Irish Government for official engagements including policy launches, hosting of State Visit ceremonial, and the inauguration of the President every seven years. The principal rooms of the State Apartments include:

;Saint Patrick's HallThis is the grandest room of the State Apartments, and contains one of the most important decorative interiors in Ireland. Formerly the ballroom of the Lord Lieutenant's administration and the location of the installation of Knights of St. Patrick, today the room is used for presidential inaugurations. It is one of the oldest rooms in the castle, dating from the 1740s, though its decoration largely dates from c. 1790, including the most significant painted ceiling in Ireland executed by Vincenzo Valdre (c. 1742–1814). Comprised of three panels, the ceiling depicts the coronation of King George III, Saint Patrick introducing Christianity to Ireland, and King Henry II receiving the submission of the Irish Chieftains.

;Throne RoomOriginally built as the Battleaxe Hall in the 1740s, it was converted for use as a Presence Chamber around 1790. The regal decoration dates from that time and from subsequent alterations in the 1830s. It contains a throne built for the visit of King George IV to Ireland in 1821.

;State Drawing RoomFormerly the principal reception room of the Lord Lieutenant and his household dating from the 1830s, today the room is reserved solely for use during visits of foreign dignitaries. Largely destroyed by fire in 1941, the room was reconstructed with minor modification in 1964–1968 by the OPW, making use of salvaged and replicated furnishings and fittings. The volume of the destroyed 18th century Presence Chamber was absorbed into the room.

;State Dining RoomAlso called the Picture Gallery, and formerly known as the Supper Room, this is the oldest room in the castle and largely retains its original decoration, having escaped major modification and fire over the years. It dates from Lord Chesterfield's building of the State Apartments in the 1740s, and was intended for use as a supper room adjoining St. Patrick's Hall and as a personal dining room. Today the room is still used for dining when conferences take place in St. Patrick's Hall. Portraits of Lord Lieutenants, mainly of the 19th century, line its walls.

;State BathroomSometimes referred to as the second Throne Room, the State Bathroom is used frequently by guests to the State Apartments. Originally a walk-in closet, it was renovated for the visit of King George IV in 1821. A solid marble toilet with gold and ivory accents (such as an ivory handle) commands the far end of the room. A similarly adorned sink and soap cupboard takes up the remaining space.

;State BedroomsThese former private quarters of the Lord Lieutenant were built as five interconnecting rooms running along the back of the building, adjoining the spine corridor that separates them from the State Drawing Room. Completely rebuilt in the 1960s following fire in 1941, the rooms maintain the original courtly sequence and today are used as ancillary drawing and meeting rooms to the principal apartments. The last dignitary to stay in the royal bedrooms was Margaret Thatcher, who spent a night there with her husband Dennis during one of the European Council meetings held in the 1980s.

;State CorridorThe most architectural space of the State Apartments, this expressive, deeply modelled corridor was originally built c. 1758 to the designs of the Surveyor General, Thomas Eyre. Based on the early 18th century corridor of Edward Lovett Pearce in the former Parliament House on College Green, it features a marching procession of vaults and arches which were originally top-lit. However an office storey was built over the skylights following complete reconstruction of the corridor in the 1960s resulting from differential settlement with the reconstruction of the adjoining Drawing Room. The corridor features exact plaster casts of the original arch detailing, and the original doorcases and fireplaces salvaged prior to rebuilding.

The State Apartments, as with Dublin Castle as a whole, are maintained by the Office of Public Works. The wider Castle complex houses, among other bodies and operations, a major conference centre, offices of the Revenue Commissioners, elements of the Office of Public Works, The National Forum on Europe, and some functions of the Garda Siochana

Famous people who stayed in the State Apartments

* Queen Victoria of the United Kingdom
* King George V of the United Kingdom and Queen Mary
* British prime minister Margaret Thatcher