Contraception was illegal in Ireland from 1935 until 1980, when it was legalised with strong restrictions, later loosened. The ban reflected Catholic teachings on sexual morality.
The encyclical Casti connubii (1930) followed the industrial production and widespread use of condoms that usually prevent fertilisation. It specified:
any use whatsoever of matrimony exercised in such a way that the act is deliberately frustrated in its natural power to generate life is an offence against the law of God and of nature, and those who indulge in such are branded with the guilt of a grave sin
Following the marketing of "the pill" in the 1960s, a Pontifical Commission on Birth Control was set up. It has often been cited that there was a majority in favour of contraception, but there is no proof of this. The encyclical Humanae vitae (1968) decreed that artificial contraception in all forms was immoral. Devout catholics are obliged not to use artificial contraception.
Owning and using contraceptive devices and pills was always legal, but they could not be sold or imported legally after a 1935 Act. During this time a loophole was used, where a device such as a condom could not be "offered for sale", but a buyer could be "invited to treat" to buy it. Also people made donations to family planning associations to obtain contraception as a "gift". The reality for almost all of the population was that contraception was illegal, and few outlets wanted to stock a product that could bring the attention of the police or public opprobrium.
In early 1971 Senator Mary Robinson (who would later become president) attempted to introduce the first bill proposing to liberalise the law on contraception into the Seanad, but was not allowed a reading, so it could not be discussed. On 31 March a number of supporters managed to get into the grounds of Leinster House and then broke into the building to register their protests. On 22 May 1971 a group of Irish feminists including Mary Kenny travelled to Belfast by rail and made their return to Dublin Connolly, laden with contraceptive devices, into a statement on the illogicality of the law. This provoked criticism from the Roman Catholic Church in Ireland; Thomas Ryan, Bishop of Clonfert, said that "... never before, and certainly not since penal times was the Catholic heritage of Ireland subjected to so many insidious onslaughts on the pretext of conscience, civil rights and women's liberation."