Grattan's Parliament refers to the Irish Parliament established in 1782, named after Henry Grattan, a prominent Irish politician. This parliament was significant because it marked a period of legislative independence for Ireland, allowing it to pass laws without interference from the British Parliament. Grattan and his supporters aimed to address issues like trade restrictions and the rights of Irish citizens. The parliament operated until 1800, when the Act of Union was enacted, merging the Irish Parliament with the British Parliament in London. This change ended Ireland's legislative independence, leading to a long struggle for Irish self-governance that continued for over a century.