Tributes have been paid after the death of Maureen Haughey, wife of former Taoiseach Charles, was announced,
Mrs Haughey was also the daughter of another ex-Taoiseach Sean Lemass and mother to sitting Dublin Bay North TD Sean Haughey.
Mr Haughey announced her passing on Twitter this morning.
"So sad to announce that my mother passed away peacefully this morning-A truly remarkable woman.May she rest in peace," he wrote.
Mrs Haughey was 91-years-old at the time of her passing.
Given her husband's controversial leadership of Fianna Fail and his long-standing affair with columnist Terry Keane, Mrs Haughey was a figure who garnered huge public sympathy.
After his death in 2006, Charles Haughey left a fortune of almost €1m to his wife.
So sad to announce that my mother passed away peacefully this morning-A truly remarkable woman.May she rest in peace pic.twitter.com/aJRIoHPUJi
— Seán Haughey (@sean_haughey) March 17, 2017
Mr Haughey's wife was the sole beneficiary of his will, according to documents lodged in the Probate Office in Dublin.
The former Taoiseach left an estate worth €1,029,955, but deductions for debts and funeral expenses brought the net value of his estate to €930,012.
After his death, Mrs Haughey lived in a house at the edge of what was once the family's 250-acre estate in Kinsealy in North Dublin.
In a rare interview, Mrs Haughey said that her father "never talked about" his role in the 1916 Easter Rising.
She opened up about her father yesterday in a rare public interview at the launch of Fianna Fáil's programme of events to commemorate the 1916 Easter Rising.
She revealed that her father, who served as Taoiseach from 1959 until 1966, rarely spoke about his involvement in Ireland's fight for independence because his brother Noel was killed just as the Civil War was due to come to an end and because it may have been too difficult for him.
"He never talked about it, only maybe when some of his old comrades came in and we'd listen in," Mrs Haughey said.
She was speaking at the event in the Royal College of Surgeons on St Stephen's Green, the same building that Constance Markievicz occupied during Easter week in 1916.
Mrs Haughey is survived by children Conor, Ciaran, Eimear, and Sean.
Fianna Fail leader Micheál Martin has extended his deepest sympathies following the death of Maureen Haughey, wife of the late former Taoiseach Charles Haughey.
Mr Martin says he and the entire Fianna Fáil organisation across the country send their condolences to the Haughey and Lemass families on the passing of a 'wonderfully warm, dignified and intelligent woman'.
He says he knew Maureen personally for many years, adding that she was a patriot who loved her country and retained a key interest in the development of Irish society.