English control was largely restricted to the area around Dublin known as The Pale until 1603, when the entire island was assimilated into the Kingdom of Ireland at the completion of the Tudor conquest.
Individuals born before April 1949 in what is now the Republic of Ireland may make formal claims to retain British subject status, though this nationality cannot be transferred by descent.
Consequently, when the BNA 1948 became effective, Irish citizens living in Northern Ireland automatically lost British citizenship, although this was not intended by the Parliament of the United Kingdom.
The Ireland Act additionally conferred CUKC status on Irish-born persons who did not receive Irish citizenship at any point prior to 18 April 1949.
[14] Irish citizens from the Republic of Ireland retained their entitlement to enter, live, and work in the United Kingdom after the end of the Brexit transition period on 31 December 2020.
Irish citizens from the Republic of Ireland are exempted from obtaining a visa or entry certificate when entering the United Kingdom and do not require approval to live or work there.
These include exemption from voting eligibility in UK (and, formerly, EU) elections,[17] and the ability to enlist in the British Armed Forces.
[18] They are also eligible to serve in non-reserved Civil Service posts,[19] be granted British honours, receive peerages, and sit in the House of Lords.
As this is a registration route, there is no requirement to pass the Life in the UK test or provide any evidence of English language knowledge.