Government of Northern Ireland (1921–1972) in the context of "Partition of Ireland"

The Government of Ireland Act 1920 (10 & 11 Geo. 5. c. 67) was an act of the Parliament of the United Kingdom. The Act's long title was "An Act to provide for the better government of Ireland"; it is also known as the Fourth Home Rule Bill or (inaccurately) as the Fourth Home Rule Act and informally known as the Partition Act. The Act was intended to partition Ireland into two self-governing polities: the six north-eastern counties were to form "Northern Ireland", while the larger part of the country was to form "Southern Ireland". Both territories were to remain part of the United Kingdom of Great Britain and Ireland and provision was made for their future reunification through a Council of Ireland. The Act was passed by the British Parliament in November 1920, received royal assent in December and came into force on 3 May 1921.

The smaller Northern Ireland was duly created with a devolved government and remained in the UK. The larger Southern Ireland was not recognised by most of its citizens, who instead recognised the self-declared Irish Republic in the ongoing Irish War of Independence. The conflict resulted in the Anglo-Irish Treaty in December 1921. Under the treaty, Ireland would leave the UK (with the option for Northern Ireland to opt out and remain in the UK, which it immediately did) in December 1922 and become the Irish Free State, which would later evolve into today's Republic of Ireland. The institutions set up under this Act for Northern Ireland continued to function until they were suspended by the British parliament in 1972 as a consequence of the Troubles.

The prime minister of Northern Ireland was the head of the Government of Northern Ireland between 1921 and 1972. No such office was provided for in the Government of Ireland Act 1920; however, the Lord Lieutenant of Ireland, as with governors-general in other Westminster systems such as in Canada, chose to appoint someone to head the executive even though no such post existed in statute law. The office-holder assumed the title prime minister to draw parallels with the prime minister of the United Kingdom. On the advice of the new prime minister, the lord lieutenant then created the Department of the Prime Minister. The office of Prime Minister of Northern Ireland was suspended in 1972 and then abolished in 1973, along with the contemporary government, when direct rule of Northern Ireland was transferred to London.

The Government of Ireland Act provided for the appointment of the executive committee of the Privy Council of Northern Ireland by the governor. No parliamentary vote was required. Nor, theoretically, was the executive committee and its prime minister responsible to the House of Commons of Northern Ireland. In reality the governor chose the leader of the party with a majority in the House to form a government. On each occasion this was the leader of the Ulster Unionist Party; such was the UUP's electoral dominance using both a simple plurality and for the first two elections, a proportional electoral system. All prime ministers of Northern Ireland were members of the Orange Order.

The Department of Agriculture, Environment and Rural Affairs (DAERA; initials pronounced as 'Dare-aa') (Irish: An Roinn Talmhaíochta, Comhshaoil agus Gnóthaí Tuaithe; Ulster Scots: Depairtment o' Fairmin, Environment an' Kintra Matthers) is a government department in the Northern Ireland Executive, the devolved administration for Northern Ireland. The minister with overall responsibility for the department is the Minister of Agriculture, Environment and Rural Affairs. The department was called the Department of Agriculture and Rural Development (DARD) between 1999 and 2016. The Minister of Agriculture previously existed in the Government of Northern Ireland between 1921 and 1972, where the department was known as the Ministry of Agriculture. The current Permanent Secretary is Katrina Godfrey.