The Attorney-General for Ireland was an Irish and then (from the Act of Union 1800) United Kingdom government office-holder. He was senior in rank to the Solicitor-General for Ireland: both advised the Crown on Irish legal matters. With the establishment of the Irish Free State in 1922, the duties of the Attorney General and Solicitor General for Ireland were taken over by the Attorney General of Ireland. The office of Solicitor General for Ireland was abolished at the same time, apparently for reasons of economy. This led to repeated complaints from the first Attorney General of Ireland, Hugh Kennedy, about the "immense volume of work" which he was now expected to deal with single-handed.
The first record of the existence of the office of Attorney General in Ireland, some 50 years after it was established in England, is in 1313 when Richard Manning was appointed King's Attorney (the title Attorney General was not in common use until the 1530s). The Attorney General was, initially, junior to the Serjeant-at-law, but since the titles King's Serjeant and King's Attorney were often used interchangeably, it can be difficult to establish who held which office at any given time. From the early 1660s, due largely to the personal prestige of Sir William Domville, (AG 1660-1686), the Attorney General became the chief legal adviser to the Crown. From time to time, especially under Elizabeth I, who thought poorly of her Irish-born law officers, the Crown adopted a policy of choosing English lawyers for this office.
The Attorney General was always a member of the Privy Council of Ireland, and a strong Attorney, like Philip Tisdall, William Saurin, or Francis Blackburne, could exercise great influence over the Dublin administration. Tisdall (AG 1760-1777), was for much of his tenure as Attorney General also the Government leader in the Irish House of Commons, and a crucial member of the Irish administration. Saurin (AG 1807-1822) was regarded for many years as the effective head of the Irish Government. In 1841 Blackburne (AG 1830-1834, 1841-1842), on being challenged challenged about a proposed appointment within his own office, said firmly that he "would not tolerate a refusal to ratify the appointment". The office of Attorney General was described at this time as being "a great mixture of law and general political reasoning"".