President Michael D Higgins has led tributes to Brother Kevin Crowley, the founder of the Capuchin Day Centre in Dublin, who died aged 90.
Br Kevin founded the Capuchin centre on Bow Street in 1969.
It provides hot meals, food parcels, clothing and day care facilities for people who are homeless and in need.
The announcement of his death "in the wonderful care of Mount Desert Nursing Home in Cork" this morning was made on the Capuchin Franciscans' website.
President Higgins said Br Kevin "made an invaluable contribution" to the people of Dublin city through the centre.
He described Br Kevin as "a warm, caring, yet fearless man, who dedicated his life to living his Christian faith in dedication to those most in need".
Br Kevin, he said, "leaves a wonderful legacy to all those whose lives to which he made such a difference".
In August 2018, Pope Francis visited the Capuchin Day Centre during his visit to Ireland.
Br Kevin told the Pope that from humble beginnings of providing 50 meals a day, it was providing over 800 meals by 2018.
He also said that the primary concern each day was the dignity and respect of each person attending the centre.
Catholic Archbishop of Dublin Dermot Farrell extended his sympathy to Br Kevin's family and members of the Capuchin order.
In a statement, Archbishop Farrell said Br Kevin's work with the day centre "staff and volunteers transformed the lives of the poor and marginalised in our city who availed of its services, from misery and despair to hope and love".
"He was always able to see Christ in the people he met. His was a love that reached out with no questions asked of those who sought assistance.
"Brother Kevin was an authentic follower of St Francis of Assisi," the archbishop added.
Taoiseach Micheál Martin said Br Kevin "was a tireless and passionate advocate for justice, dedicating his life to helping those in need" and "worked selflessly, and with good humour, for 53 years providing help to vulnerable people" in the Capuchin centre.
"His compassion, devotion and non-judgmental approach to helping the marginalised was unwavering.
"He was an inspiring and humble man" who "truly lived the gospel", Mr Martin said in a statement.
Ireland has lost a wonderful person, someone who brought care and humility to his work, Minister for Public Expenditure Jack Chamber told the Dáil.
Sinn Féin leader Mary Lou McDonald described Br Kevin as a true legend and a champion of the poor.
Labour Party leader Ivana Bacik said that he did "immense work", had "a great sense of humour" and will be sadly missed.
A book of condolence for Br Kevin will be opened tomorrow until Friday at the Mansion House, the Lord Mayor of Dublin said.
Ray McAdam described Br Kevin as one of the city's "most compassionate and selfless figures", adding that he was a "beacon of compassion and dignity for those experiencing homelessness" in the capital.
He said Br Kevin had received the Honorary Freedom of the City from former mayor Christy Burke in 2015.
Funeral to be held on Saturday
Funeral arrangements for Br Kevin have been confirmed.
His remains will arrive at St Mary of the Angels Church on Church Street in Dublin at 5pm tomorrow and will repose there on Friday.
Requiem mass will be on Saturday at 11am followed by burial in Dardistown Cemetery.