Tanaiste Eamon Gilmore has led a chorus of tributes to institutional abuse campaigner Christine Buckley, who has died aged 67.
Ms Buckley, who co-founded the Aislinn Centre for abuse survivors, died at St Vincent's Hospital following a long battle with cancer.
She was a woman of courage and dignity who had helped to make Ireland a better place, said Mr Gilmore.
"Christine suffered greatly as a child growing up in the industrial school system in the Ireland of the 1950s," he said.
"But as an adult she played a pivotal role in shining a light on the abuse suffered by children in the industrial schools and in campaigning on behalf of the many survivors of institutional abuse."
Ms Buckley featured in the landmark Dear Daughter documentary broadcast on RTE in 1996 which recounted the horror of her time as a child in the Sisters of Mercy-run orphanage in Goldenbridge, Dublin.
"This state was a very cold place for children such as Christine who were placed in the care of the state," said Mr Gilmore.
"Yet Christine's courage and dignity in speaking out has made Ireland a better place.
"Her profound act of bearing witness has paved the way for other survivors of institutional abuse to tell their stories and to seek redress for the abuse that was perpetrated in the industrial schools system."
Ms Buckley was one of the first survivors of institutional abuse to go public about her experience, which helped turned the spotlight on child abuse within Catholic Church-run organisations.
She campaigned for decades on behalf of other survivors.
Children's Minister Frances Fitzgerald said Ms Buckley was a courageous and consistent campaigner for child protection and children's rights.
"As a survivor of institutional abuse, Christine led the charge to lift the veil on Ireland's dark past and shameful legacy of child abuse," she said.
Ms Buckley is survived by her husband Donal and three grown-up children, Darragh, Conor and Cliona.
Enda Kenny said Ms Buckley was a "person of immense courage".
Speaking in Downing Street after talks with Prime Minister David Cameron, the Taoiseach said: "I'm sorry to hear of Christine's death.
"I think she was a person of immense courage who was responsible as a pioneer in bringing into public awareness the question of institutional abuse.
"You would not have had a redress scheme to bring some closure and some comfort to people who were abused institutionally were it not for Christine Buckley."