There is no founding date for the United Kingdom. No declaration, no constitution, no single act created it. Instead, the UK emerged through centuries of unions, conquests, and legislation — a process still unfolding.
| Date | Event | Result |
|---|---|---|
| 1536/1543 | Laws in Wales Acts | Wales incorporated into England |
| 1603 | Union of Crowns | James VI/I rules Scotland & England personally |
| 1707 | Acts of Union | Great Britain formed (England+Wales + Scotland) |
| 1801 | Acts of Union | United Kingdom of Great Britain & Ireland |
| 1922 | Anglo-Irish Treaty | Irish Free State secedes |
| 1927 | Royal & Parliamentary Titles Act | United Kingdom of Great Britain & Northern Ireland (current name) |
| 1998 | Good Friday Agreement | NI power-sharing; cross-border bodies |
| 1999 | Devolution Acts | Scottish Parliament, Welsh Assembly, NI Assembly |
| 2014/2016 | Indyref / Brexit | Constitutional stresses ongoing |