An Act to prevent the further Growth of Popery, commonly known as the Popery Act or the Gavelkind Act, is an act of the Parliament of Ireland that receives royal assent on March 4, 1704. It is designed to suppress Roman Catholicism in Ireland (“Popery“). William Edward Hartpole Lecky calls it the most notorious of the Irish Penal Laws.

Inheritance in traditional Irish law uses gavelkind, whereby an estate is divided equally among a dead man’s sons. In contrast, English common law uses male primogeniture, with the eldest son receiving the entire estate. The 1704 act enforces gavelkind for Catholics and primogeniture for Protestants.

Two separate bills “to prevent the further Growth of Popery” are introduced in the parliamentary session of 1703–04. One originates with the Privy Council of Ireland and is referred on July 4, 1703, to the Attorney-General for Ireland. The other is introduced as heads of a bill in the Irish House of Commons on September 28, 1703, and is sent to the Lord Lieutenant of Ireland on November 19. Under Poynings’ Law, both bills are transmitted to the Privy Council of England for approval. Formally, one bill is vetoed, and the other is returned to Dublin with amendments. A lack of surviving documentation makes it impossible to determine which of the two has which fate. The approved bill is engrossed on January 20, 1704, presented in the Commons on February 14, sent to the Irish House of Lords on February 25, and given royal assent on March 4.

Sir Theobald “Toby” Butler, the former Solicitor-General for Ireland, a Roman Catholic, makes a celebrated speech at the bar of the Commons denouncing the act as being “against the laws of God and man… against the rules of reason and justice.” Other eminent Catholic lawyers like Stephen Rice also denounce the measure but to no avail.

Charles Ivar McGrath says that while the Popery Act has “evident … negative effects,” specific research is lacking, and that it is intended more to prevent an increase in Catholic landholding than encourage further decrease. The Catholic share of land had already fallen from 60% before the Irish Rebellion of 1641 to 22% before the Williamite War in Ireland to 14% in 1704. The figure of 5% in 1776 given in Arthur Young‘s Tour in Ireland is probably an underestimate, although in 1778 only 1.5% of rent is paid to Catholics.

Catholic gavelkind cements a tradition of farm subdivision, which persists beyond the act’s repeal and contributes to the Great Famine of the 1840s.

The act is “explained and amended” by a 1709 act, 8 Anne c. 3 (I), which specifies certain time limits left ambiguous by the original act, and closes some loopholes used by Catholics to remain beneficial owners of nominally Protestant property.

A 1719 act, 6 Geo. 1. c. 9 (I), indemnifies officials who have not hitherto subscribed to the oath required by the Popery Act. The time period for Dissenters subscribing to the oath is routinely extended, initially by an Indemnity Act at the start of each biennial parliamentary session. Similar acts are passed by the British parliament, and after the union the UK parliament continues the practice.

From the late 18th century Roman Catholic relief bills ease the Penal Laws, by explicit or implicit repeal and replacement. In 1772, Catholics are allowed to lease up to fifty Irish acres of bog-land for up to 61 years. The 1704 oath of allegiance for Catholics is replaced in 1774. Gardiner’s Act, the Leases for Lives Act 1777, implicitly repeals many other provisions of the 1704 act. Some are replaced with less onerous restrictions. The sacramental test is repealed for Dissenters in 1780. The Roman Catholic Relief Act 1782 repeals section 23 of the 1704 act. Another act of 1782 allows lay Catholics to be guardians of Protestants. Most restrictions on intermarriage are removed by the Roman Catholic Relief Act 1792. Many Penal Laws are repealed in general terms by the Roman Catholic Relief Act 1793. The sacramental test for Catholics is effectively replaced by the 1774 oath.

The Roman Catholic Relief Act 1829 abolishes the declaration against transubstantiation and specifies a new public oath for Catholics, explicitly permitting Catholics to hold Irish civil or military offices other than Lord Lieutenant and Lord Chancellor of Ireland, with the same oaths as required of non-Catholics (in addition to the new Catholic oath).

The Criminal Law Commission‘s 1845 report on oaths says sections 1, 3, and 6 of the 1704 act have fallen into disuse and should be repealed. The Religious Disabilities Act 1846, passed in consequence of the committee’s report, explicitly repeals provisions of sections 1, 3, and 4 of the 1704 act.

The Popery Act is explicitly repealed as obsolete by the Promissory Oaths Act 1871, with the exception of section 25, which is made redundant by the coming into force in 1871 of the Irish Church Act 1869 and is repealed by the Statute Law Revision (Ireland) Act 1878.