Dublin Castle administration

Dublin Castle was the centre of the government of Ireland under English and later British rule. "Dublin Castle" is used metonymically to describe British rule in Ireland. The Castle held only the executive branch of government and the Privy Council of Ireland, both appointed by the British government. The Castle did not hold the judicial branch, which was centred on the Four Courts, or the legislature, which met at College Green till the Act of Union 1800 and thereafter at Westminster.

The head of the administration was variously known as the Justicar, the Lord Deputy, from the seventeenth century the Lord Lieutenant of Ireland, and later the Viceroy. Before 1707 he represented the government of the Kingdom of England, then that of the Kingdom of Great Britain, and finally from 1801 that of the United Kingdom. He was also the personal representative in Ireland of the monarch.

By the nineteenth century, the Lord Lieutenant was declining in importance by comparison with his chief aide, the Chief Secretary for Ireland. By the late nineteenth century the Lord Lieutenant was sometimes, but not always, a member of the British cabinet, but the Chief Secretary invariably was a member.

The Government of Ireland Act 1920 gave the Lord Lieutenant a new role, that of the Crown's representative in the two new Irish UK regions of Northern Ireland and Southern Ireland. However, the Irish War of Independence and subsequent Civil War meant that Southern Ireland's institutions never came into operation and Northern Ireland's institutions were not established until 1921. Upon the independence of the Irish Free State from the United Kingdom in 1922, the Lord Lieutenancy was abolished, with its functions being transferred to the two new offices of Governor-General of the Irish Free State and Governor of Northern Ireland respectively.

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