It was subject to an Irish executive, presided over by the English/British selected Lord Lieutenant of Ireland (previously called the 'Lord Deputy'), which was ultimately answerable not to it but to the English/British Government in London.
Its legislature, the General Assembly, met once a year in Kilkenny to review the work of the executive branch (which it appointed) - the Supreme Council.
This was a revolutionary parliament formed by Irish MPs elected to the British House of Commons, who assembled in Dublin in January 1919.
The House of Commons was officially based in the Royal College of Science in Dublin, now the Irish Government Buildings.
However the Commons only met on a handful of occasions, primarily to ratify the Treaty in January 1922 and confirm Michael Collins as head of the Provisional Government.
In 1924, the new Free State under Cosgrave bought Leinster House as a temporary seat of parliament, pending the erection or conversion of an alternative.
One major contender for the location was Royal Hospital Kilmainham, a former soldiers' home that ultimately became a modern art gallery.