Although England's involvement in Ireland began with the arrival of Norman settlers in the 12th century, its direct authority over Irish affairs - via the Irish Parliament - varied from century to century.
By the end of the 15th century English authority in Ireland had all but disappeared, but in 1494 an Irish Parliament meeting at Drogheda passed Poynings' Law, named after Sir Edward Poynings, the recently-arrived chief governor in Ireland. It would survive, with modifications, until 1782.
Under the terms of Poynings' Law, all Irish Bills had to be submitted by the English chief governor in Ireland to the King and Privy Council, via the English Parliament.
There they could be amended and approved, or rejected. Only Bills approved and returned to Ireland under the Great Seal of England were presented to the Irish Parliament.
The original purpose of had been to to curb the independence of Ireland's Anglo-Norman chief governors. However, the Irish Parliament resented its restrictive effect.
Although delegates from the Irish Parliament could influence each proposal as it was debated in the Privy Council, the final form of each Bill was effectively decided in the English Parliament.
Beginning with the 1536 Protestant Reformation, King Henry VIII went even further. Church legislation from the English Reformation Parliament was extended to Ireland, and in 1541 Henry upgraded it from a lordship to a full kingdom.
The Irish parliament “most willingly and joyously” consented to a Bill conferring on him the title King of Ireland.