Taoiseach Enda Kenny has said the Government wants to hold an extensive inquiry into mother-and-baby homes that will cover a broad range of societal issues.
The Cabinet agreed today to establish a Commission of Investigation into the homes.
Speaking in the Dáil, Mr Kenny said: "What's emerged about mother-baby homes across the country is a less than glorious episode from the country's past."
He said children born outside marriage were treated as a different species for decades after the foundation of the State.
However, Mr Kenny warned against an overly legal response that would end up in an expensive assessment of files already available.
He said the Government would consult widely to find the best structure for the Commission.
Human rights groups said it is vital the State deals with the issue of how some women and children were treated for much of the last century
In Tuam, Co Galway, where the latest focus on mother-and-baby homes began, local historian Catherine Corless has been fielding calls from across the world in recent weeks.
This afternoon, she described the Cabinet decision as great news, which would be particularly welcomed by groups around the country that had been seeking to find out more about such homes.
Amnesty International said the timely approach of the State to investigate the issues was notable.
The ISPCC said it hoped the investigation would shed light on another dark period in Irish history.
The Children's Rights Alliance described the inquiry as the first step in establishing the truth of what happened in the homes.
In particular, the organisation called for a detailed examination regarding clinical trials on children.
Minister for Children Charlie Flanagan, who made the announcement this afternoon, said the object of the investigation will be to seek the truth, to catalogue the facts and to explain exactly what happened in mother-and-baby homes.
He said the revelations in Tuam had been deeply disturbing and had shown up a really tragic period in Irish life and society.
The inquiry will cover all mother-and-baby homes, including the Protestant-run Bethany Home, along with an examination of any vaccine trials.
The interdepartmental scoping exercise will report back by 30 June and then the Government will draw up the terms of reference.
When asked about the possibility of a criminal investigation into what happened, Mr Flanagan said that is entirely a matter for gardaí.
Speaking on RTÉ's News at One, Mr Flanagan said it is too early to say who will lead the commission, but that he has some names in mind.
He said it is important that a light be shone on "these dark periods".
Mr Flanagan said he hopes the inquiry will examine all issues, including high mortality rates, burial practices following these deaths, legal circumstances around adoptions and the question of the conducting of clinical trials.
It is important to get political and national consensus on the terms of reference for the commission of investigation, he said.
There are complex legal issues and complex social issues involved, he said, adding that it was important first-and-foremost to establish the facts.
Mr Flanagan urged church authorities to hand over all documents and records to the inquiry.
He did not put a time frame on the duration of the inquiry and said questions around compensation were also premature.
Fianna Fáil spokesperson on children Robert Troy said any investigation needs to be done in an extremely sensitive manner and should be above party politics.
Mr Troy said the women who stayed at the homes had nothing to be ashamed of.
He said they should be assured that if they come forward, they will have confidentiality, and nobody would be judging them.
He said Fianna Fáil party members had been meeting constituents, who were former residents of the homes, and that these people were terrified that a full independent inquiry could identify them.
Sinn Féin's Caoimhghin O'Caoiláin said it is a dreadful fact that women and children were "treated as outcasts and non-people" in these institutions.
His party colleague Mary Lou McDonald said the religious institutions and organisations that undoubtedly were the social norms of Ireland in past decades need to be scrutinised.
But she added that when when you pare it all back, it is about the State's responsibility.
This inquiry is all about the kind of Ireland that was but this investigation will be all about the kind of Ireland that is, she said.
The Philomena Project also welcomed the Government's announcement of an inquiry.
The project has fully endorsed all calls for an independent statutory inquiry into the homes, particularly the issue of forced adoption.
Earlier it emerged that extensive records from the Bon Secours mother-and-baby home in Tuam make no reference to burial locations for children who died there.
The child and family agency, Tusla, has several original ledgers from the home containing a range of administrative data.
It is understood the material was initially passed to Galway County Council when the home closed in 1961 and would have been subsequently transferred to the Western Health Board and then the Health Service Executive, before coming into the care of Tusla at the beginning of this year.
There are a total of nine ledgers containing information about discharges and admissions to the home between 1921 and 1961.
These list the names of mothers, the dates on which they were admitted and discharged as well as the name and date of birth of their children.
The agency also has possession of quarterly returns from the home to Galway County Council between 1919 and 1961.
In these documents, the total number of mothers and children in the home are listed for each three-month period.
In the event of deaths having occurred in any quarter, these would be detailed. In many cases, the cause of death is recorded but information was not always consistently maintained in this regard.
There are no burial records in the returns and no mention of burial locations in any of the other material in the care of Tusla.
Several maternity registers from Tuam dating from 1935 to 1961 are also being stored. These contain medical records of births.
It is understood that the death of a baby during childbirth or a stillbirth would have been registered here.
A fourth set of documents has information relating to children who were "boarded out" from the home between August 1929 and November 1959.
This was the term used to describe the modern day practice of fostering. This data also details the situation regarding babies that were born in Tuam and placed for adoption.
All of the documents are being stored in a secure, fireproof room in one of the agency's Galway offices.
The material is held in trust by Tusla, which has a duty of care to look after the information and to ensure that only those who are entitled to look at it gain access.
The information contained in the books is strictly confidential and subject to usual data protection regulations. It can only be accessed by individuals whose details are contained in the files.
However, a spokesperson said it would be made available to any State inquiry and there would be no legislative barrier to this. It is likely that personal details would be redacted if this were to happen.