The declatory act defines the right of the british parliament to legislate for ireland

An Act for the better securing the dependency of the Kingdom of Ireland on the Crown of Great Britain (6 Geo. 1. c. 5) was a 1719 Act passed by the Parliament of Great Britain which declared that it had the right to pass laws for the Kingdom of Ireland, and that the British House of Lords had appellate jurisdiction for Irish court cases. It became known as the Declaratory Act, and opponents in the Irish Patriot Party referred to it as the Sixth of George I (from the regnal year it was passed).

Legal and political historians have also called it the Dependency of Ireland on Great Britain Act 1719 or the Irish Parliament Act 1719. Prompted by a routine Irish lawsuit, it was aimed at resolving the long-running dispute between the British and the Irish House of Lords as to which was the final court of appeal from the Irish Courts.

Along with Poynings’ Law, the Declaratory Act became a symbol of the subservience of the Parliament of Ireland, and its repeal was long an aim of Irish statesmen, which was finally achieved for Anglican Irish as part of the Constitution of 1782.