Today's referendum is the just latest in a litany of occasions the Irish people have been asked to vote on proposals to amend the 1937 Constitution.

In July 1937, 56% of the electorate voted in a plebiscite to approve the adoption of the draft constitution.

Since then, the Irish people have been asked to vote on subjects as diverse as Ireland’s joining the EEC back in May 1972 to cutting judges’ pay during the economic crisis in October 2011.

Social issues have also been a feature of referendums including the removal of the "special position" of the Catholic Church in December 1972, legalising divorce in November 1995 and same-sex marriage in May 2015.

Here are five things to know about previous referendums:

1.  Votes about votes

Eight different proposals have been put to the people about how Ireland should vote in elections. Two of them were unsuccessful attempts by Fianna Fáil to replace the PR-STV electoral system with single-member constituencies and a first past the post system. Both of these referendums were defeated in June 1959 and October 1968. 

The 1959 referendum took place on the same day Eamon de Valera was elected President. As Mr DeValera was retiring as taoiseach, Fianna Fáil was concerned that it would find it more difficult to win an overall majority of seats under the PR system without his towering presence at the helm.

It is said this fear of losing dominance in future election motivated Fianna Fáil to seek to abolish PR. But almost 60 years later the same PR-STV system is still in place.

2.  To ignore or to invoke

When the new Seanad was established under the 1937 constitution, six seats were elected by university graduates – three from the National University of Ireland and three from Trinity College Dublin.

In July 1979, the Irish people voted on a proposal which would allow for the re-organisation of the university seats in the Seanad.

The proposal to extend the Trinity and NUI universities' representation to other third level institutions was voted in with a resounding 92.4% in favour. Almost 40 years later, and despite the publication of over a dozen reports on Seanad reform in the interim, the provision approved in that 1979 referendum has never been invoked.

On two occasions the Irish people have been asked to vote for a second time on the same proposal – the Nice and Lisbon Treaty referendums.

The Nice Treaty was rejected by 54% to 46% in June 2001. But it was passed by 63% to 37% the following October.

In June 2008, the Lisbon Treaty was initially rejected by 53% to 47% and passed the following October by 67% to 33%.

3. Highs and lows

There was a staggering 75.8% turnout for the plebiscite on the new Constitution in July 1937. But the largest turnout for a referendum came in May 1972. In the referendum that decided Ireland would join the European Economic Community there was a 70.9% turnout with 83.1% voting in favour of the proposal.

The lowest turnout for a referendum came in July 1979 when just 28.6% of the electorate came out to vote on a proposal to extend Seanad university representation to other third-level institutions and another technical amendment on child adoption. 
 
4. Tight margins and landslides

It has been said that rain in the west of Ireland on polling day swung the divorce referendum in 1995.

The theory goes that the rain meant less people came out vote, in what was then perceived to be the more conservative western sea board.

Whatever the veracity of that theory, it is certain that lowest majority in favour of a referendum proposal was in that November 1995 poll.

50.3% (or 818,842 people (voted in favour of introducing divorce, while 49.7% (or 809,728) voted against the proposal. 

So a margin of just 9,114 votes won the day.

The largest majority in a referendum came in July 1979.

That referendum was on child adoption.

A few years earlier an anomaly emerged that adoption orders made by the Adoption Board could be found to be unconstitutional for the technical reason that they were not made by a judge or court. The amendment was required to clear up this anomaly.

A massive 99% or 601,994 people voted in favour of the proposal with just 1% or 6,265 people voting against it.

5. The death penalty, blasphemy and women's role in the home

Ireland is one of the few countries in the world where each amendment to the Constitution requires the consent of the people. 

We have had referendums on proposals as varied as the 2001 referendum prohibiting the re-introduction of the death penalty to the 2015 proposal to lower the minimum age for the presidency from 35 to 21. 

That proposal came from the Constitutional Convention which sat between 2012 and 2014 to discuss various proposals to amend the constitution.

Whatever the result this weekend, more referendums are already in the offing for the next few years.

Among them is one on removing the offence of blasphemy from the Constitution and replacing it with a ban on incitement to religious hatred. Another will involve amending article 41.2.1 on the role of women in the home and inserting more gender-inclusive and gender-neutral language.

Ireland's long relationship with the referendum looks set to continue.