Hillsborough Castle, which is located in the village of Hillsborough in north-west County Down, is not a true castle. It is a Georgiancountry house built in the 18th century for the Hill family, Marquesses of Downshire, who owned it until 1922, when the 6th Marquess sold the mansion and its grounds to the British government. In buying it, the government solved a practical problem. Under the Government of Ireland Act 1920 a new, distinct region of the United Kingdom called Northern Ireland had been created within the traditional province of Ulster but minus three counties—Cavan, Donegal, and Monaghan—which became part of the Irish Free State. Executive authority had been vested for both Northern Ireland and sister region Southern Ireland in the Lord Lieutenant of Ireland, who was supposed to be one of two all-Ireland features in the new home rule structure. However, that office was abolished in a law change following the Anglo-Irish Treaty of 1921, which in effect aborted Southern Ireland and established the Irish Free State. A new office for Northern Ireland alone was created, that of Governor of Northern Ireland. As the Viceregal Lodge in Dublin became unavailable, physically and politically, a new residence was needed. Hillsborough Castle, though outside the largest city of Northern Ireland, Belfast, was deemed a suitable location. After some renovations, the first governor, The 3rd Duke of Abercorn, moved in during 1925. Upon becoming the official residence of the governor, the building was officially renamed Government House.
Following the decision to abolish Northern Ireland's devolved system of government and institute direct rule from London, all Northern Irish governmental posts, including that of Governor and Prime Minister of Northern Ireland, were abolished. Those two posts were in effect combined to create the office of Secretary of State for Northern Ireland. As the Queen's representative, the Secretary of State resides in Hillsborough Castle – as do junior ministers, though members of the Royal Family, when visiting Northern Ireland, stay there also. Queen Elizabeth II and the Duke of Edinburgh stayed in Hillsborough Castle during their visit to Northern Ireland as part of the Golden Jubilee tour of the United Kingdom in 2002.
Investitures
In 2014 the Prince of Wales held an investiture at Hillsborough Castle, the first one to be held in Northern Ireland since the venue became a royal palace.
Hillsborough Castle became the controversial location of the signing of the Anglo-Irish Agreement on November 15th, 1985. Irish TaoiseachGarret FitzGerald believed that signing the agreement in Hillsborough Castle would mollify unionist opposition to the Agreement somewhat. However, many unionists took offence at the signing of the agreement in the Throne Room of the castle, igniting their opposition further.
broke new ground when she opened the extensive grounds of the castle to the public. Previous Secretaries of State had not done so because of the fear of Provisional IRA attack. The security impact on the castle can be seen in the presence of bullet-proof glass in plastic frames in front of the Georgian windows at the public front of the building.
Prominent visitors
Apart from members of the British Royal Family and politicians from Northern Ireland, elsewhere in the United Kingdom or from the Republic of Ireland, some international figures have visited or stayed at the castle. The then President of the United States, George W. Bush, visited the castle in 2003. Within the grounds of the castle are number of trees planted by residents of, and visitors to, the estate. These include:
