The funeral of Austin Currie has been told he was a "true giant of civil rights".
President Michael D Higgins, Tánaiste Leo Varadkar, Minister for Foreign Affairs Simon Coveney, Minister for Justice Helen McEntee, SDLP leader Colum Eastwood and a representative of Taoiseach Micheál Martin were among those who attended the service at the Church of the Immaculate Conception in Allenwood, Co Kildare.
Mr Currie's daughter Estelle said he was a hero to so many.
"Wow daddy, 82 years young, what a force for change you have been, what a force for good," she told mourners.
"There have been so many tributes paid since Tuesday - the finest, fearless, immense courage, a true giant of civil rights and constitutional politics, one of its founding fathers. Daddy was always a hero to us, now we know he was a hero to so many others too."
Mr Currie died in his sleep at his home in Derrymullen, Co Kildare, on Tuesday.
He had recently celebrated his 82nd birthday.
Tributes have been paid across Ireland to Mr Currie, one of the key figures in the civil rights movement in Northern Ireland who also helped to found the nationalist SDLP party and was elected to parliament on both sides of the border.
Another service will take place tomorrow morning at St Malachy's Church in Edendork, Co Tyrone, before burial in the adjoining cemetery.
Mr Currie was born in Co Tyrone, the eldest of 11 children.
His decision to squat at a council house in Caledon in June 1968 is widely seen as the beginning of the civil rights movement, which challenged inequality and discrimination against Catholics.
He went on to create the SDLP along with John Hume and Gerry Fitt in 1970.
In 1989, he won a seat in Dublin West for Fine Gael and pursued a career as TD and minister in the Dáil until he retired in 2002.
He is survived by his wife Annita and their five children, including their daughter Senator Emer Currie.
