The referendum’s outcome brings to a close a 35-year political war that convulsed Irish politics in a succession of bitter controversies and referendum campaigns.
During it, political parties were split, society was riven by bitter divisions and a succession of referendums failed to resolve the issue in a conclusive manner.
The campaign to have a constitutional ban on abortion burst on to the political stage in 1981, as the country faced an economic crisis that prompted three general elections over 18 months.
Fianna Fáil leader Charles Haughey endorsed the Pro-Life Amendment Campaign and in 1982 his government produced the wording that was ultimately inserted into the Constitution.
Fine Gael leader Garret FitzGerald, in the face of a whispering campaign suggesting that he was "soft on abortion", endorsed that wording.
The young Labour Party leader, Dick Spring, backed by his more experienced deputy leader, Barry Desmond, opposed it from the start and refused to endorse it. For that Labour paid a heavy political price.
When Fine Gael and Labour emerged with a clear majority in the election of November 1982, FitzGerald moved to implement the commitment he had given to the PLAC campaign.
Barry Desmond, as minister for health, refused to have anything to do the drafting of the amendment and the poisoned chalice was handed by FitzGerald to minister for justice Michael Noonan.
The then attorney general, Peter Sutherland, who had to draft the amendment, concluded that the original wording was ambiguous and might even have the opposite effect to the one intended. He was ultimately proved correct on that.
Sutherland drafted a new wording that led to political uproar. Fine Gael and Labour were split and Haughey, with the unanimous backing of the Fianna Fáil parliamentary party, managed to have the original wording passed by the Dáil.
The Eighth Amendment Bill was passed by 87 votes in favour to 13. A large number of Fine Gael TDs abstained. The majority of Labour TDs voted against, joined by Fine Gael's Alan Shatter and Monica Barnes.
Hostile reaction
Desmond recalls being targeted in a particularly vicious way during the subsequent campaign. “I was picketed at my clinics; the phone calls were toxic and the pulpit attacks widespread. My wife, Stella, and I protected our children from the flood of gruesome foetal images in the door. We will never forget the hostility.”
While the amendment was passed by a two-to-one majority, the bitter nature of the campaign proved off-putting for many voters and the turnout was just 54 per cent.
Abortion soon returned to the political agenda. Before the Fianna Fáil-led government signed up to the Maastricht Treaty in February 1992, the anti-abortion campaign had raised concerns that it would have implications for Ireland's ban on abortion.
A protocol was attached to the treaty at the request of the Irish government, spelling out that there were no implications for abortion one way or another. The issue was raised repeatedly during the referendum on the treaty. It was just the first in a series of European referendums that were to be sidetracked by the abortion issue.
Far more significantly, in early 1992 the X case burst on to the political agenda just after Albert Reynolds had taken over as leader of Fianna Fáil and Taoiseach in early 1992.
That case convulsed the country, and when the Supreme Court ruled that the threat of suicide represented a threat to the life of a mother and consequently abortion could be permitted in such cases, the issue went back to the public.
The government proposed three referendums, one on the right to information about abortion, one on the right to travel to avail of the option, and a third on the so-called substantive issue, which modified the Eighth Amendment to take account of the Supreme Court decision on suicide.
Another bitter campaign ensued but the public mood was very different from that of 1983. Voters endorsed the right to information and travel but rejected the government’s proposal on the substantive issue. Opposition to this measure came from campaigners in favour of permitting abortion and those most adamantly opposed, who believed it opened the door to abortion.
European referendums
The result was stalemate but the issue would not go away. It featured again in European referendum campaigns, with anti-abortion campaigners joining those with worries about Irish neutrality. The result was that two referendums on Europe were defeated and had to be rerun, with the issues clarified.
Bertie Ahern's government in the late 1990s made another effort to sort out the abortion issue. Under the chairmanship of Brian Lenihan jnr, an All Party Oireachtas Committee produced a wording to deal with the contradictions at the heart of the existing constitutional provision.
It was essentially a rationalisation of the status quo and met with strong opposition from pro-choice groups, who were again joined by the most vociferous anti-abortion campaigners opposed to any moderation of the existing regime.
This Catholic hierarchy, though, backed this attempt to amend the Constitution but it went down to the narrowest of defeats in 2002, indicating that the public mood had shifted significantly since 1992.
The Fine Gael-Labour Government led by Enda Kenny finally moved to legislate on the issue in 2013. This legislation, which emerged after long Oireachtas committee hearings, formally approved abortion in cases where a mother's life was in danger, including the threat of suicide.
Despite its restricted focus, the legislation led to another political convulsion, with a number of Fine Gael TDs defying the party whip and being expelled as a result.
Following the passage of that legislation the campaign to repeal the Eighth Amendment grew more confident. The proposal to delete it from the Constitution emerged after Leo Varadkar became Taoiseach, and he started the process that brought the longest war to an end.