The Government of Ireland Act 1920 is 100 years old on Wednesday. This marked the 1st time legislative power was devolved within UK, 80 yrs before the creation of Scottish Parliament & National Assembly for Wales (now @SeneddWales). Here's a thread...1/14

https://www.legislation.gov.uk/ukpga/Geo5/10-11/67/contents/enacted

As my new @commonslibrary Insight blog details, the 1920 Act was significant because it:

1) Established the part of the UK still known as Northern Ireland;
2) Created a border on the island of Ireland;
3) Reconstituted the UK as it is today 2/14 https://commonslibrary.parliament.uk/100-years-since-the-government-of-ireland-act-1920/

My related @commonslibrary briefing (more of a book...) on the @UKParliament and Northern Ireland, 1921-2021, looks at the origins of the 1920 Act. It also charts the constitutional development of Northern Ireland over the following century 3/14 https://commonslibrary.parliament.uk/research-briefings/cbp-8884/

Civil servant Kenneth Bloomfield said the 1920 Act was 'aspirationally unitary'. This was because Section 2 provided for a 'Council of Ireland' which could have led to an all-Ireland devolved parliament 4/14

https://www.legislation.gov.uk/ukpga/Geo5/10-11/67/section/2/enacted

The Council of Ireland wasn't constituted. In December 1922, when most of Ireland (the Irish Free State) seceded from the UK, the 1920 Act was amended so that it applied only to Northern Ireland 5/14

https://www.legislation.gov.uk/ukpga/Geo5Sess2/13/2/contents/1991-02-01

The Parliament of Northern Ireland consisted of the King, a 52-member House of Commons and an indirectly elected Senate. The Commons was initially elected by single transferable vote, but this changed to first past the post in 1929 6/14

Executive power was vested in the monarch, represented in Northern Ireland by a vice-regal Governor. They in turn delegated that authority to ministers in the Government of Northern Ireland, all of whom had to be members of the Privy Council of Northern Ireland 7/14

King George V opened the first session of the Parliament of Northern Ireland in June 1921. After 1932, a Westminster-style state opening took place every year or so at the custom-built 'Stormont', where the Northern Ireland Assembly sits today 8/14

Unlike @UKParliament, Northern Ireland ministers could speak (but not vote) in both the Stormont House of Commons and Senate, which enabled the same minister to guide legislation through both Houses 9/14

If the Senate rejected a Bill in two successive sessions, Section 17 of the 1920 Act provided for a joint sitting of Senate and the Commons. A majority vote would pass the Bill. This 'deadlock' provision was never used 10/14

https://www.legislation.gov.uk/ukpga/Geo5/10-11/67/section/17/enacted

Another provision of the 1920 Act, Section 8(4)(b), allowed someone who was neither an MP nor a Senator to become a minister, but only for six months. Two non-Ulster Unionist ministers were appointed on this basis in 1971 11/14

https://www.legislation.gov.uk/ukpga/Geo5/10-11/67/section/8/enacted

The 1920 Act also included a religious discrimination clause. This was intended to protect Northern Ireland’s Catholic minority, but there were many allegations of discrimination by the Parliament and Government of Northern Ireland between 1921-72 12/14

http://tinyurl.com/ybzw5cmk 

Section 75 of the 1920 Act stated Westminster’s legislative supremacy, but at no point did it legislate on 'transferred' (or devolved) matters without Stormont’s consent. This 'self-denying ordinance' was similar to today's Sewel Convention 13/14

https://www.legislation.gov.uk/ukpga/Geo5/10-11/67/section/75/enacted

As the security situation deteriorated after 1969, the UK Government became more closely involved in Northern Ireland affairs. Stormont was at first prorogued & then abolished in 1972-73. What remained of the 1920 Act was repealed in December 1999 14/14

https://www.legislation.gov.uk/ukpga/1998/47/schedule/15