The Act of Union Abolishes the Irish Parliament
Two parliaments vote themselves into one, and Ireland becomes formally part of the United Kingdom
Quick facts
- Effective date
- 1 January 1801
- Passed by
- Parliament of Great Britain and Parliament of Ireland, 1800
- Irish MPs in united Commons
- 100
- Irish peers in united Lords
- 28, plus 4 rotating bishops
What happened
Following the 1798 rebellion, the British government under Pitt the Younger pushed for a full legislative union between Great Britain and Ireland rather than continued separate Irish self-government under the crown. Parallel Acts of Union were passed by the Parliament of Great Britain and the Parliament of Ireland in 1800, uniting the two kingdoms into the United Kingdom of Great Britain and Ireland with effect from 1 January 1801. The Act abolished the Irish Parliament in Dublin outright; the united Parliament in London absorbed 100 Irish members into its House of Commons and 28 Irish representative peers plus four rotating Church of Ireland bishops into its House of Lords. The legislation itself states plainly that the two kingdoms were to be joined permanently from that date.
Why it matters
The Act of Union ended five centuries of a separate, if subordinate, Irish parliamentary tradition and moved all Irish legislative decisions to Westminster, a centralization of power that Irish nationalists spent the following 120 years trying to reverse, first through Home Rule and eventually through outright independence.
How we know
The Act of Union survives as an actual piece of legislation passed by both parliaments in 1800, its text preserved in the UK's statute record, and its legislative process is documented in the parliamentary records of both the British and Irish parliaments of the period.
Sources
- UK Legislation, The National Archives. Act of Union (Ireland) 1800 · Primary source (author-declared)legislation.gov.uk · Cited as a "primary" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- National Army Museum (UK). Irish Rebellion of 1798 · Reputable sourcenam.ac.uk · The domain "nam.ac.uk" is on our Reputable source registry. · Link is live and its text matches the event's key terms (Jul 2026)
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Part of a timelineHistory of Ireland24 events · A passage tomb older than the pyramids, an alphabet of monks and manuscripts, and an island fought over, planted, starved, and finally split in twoView all →