Live coverage of the mass is broadcasting on RTÉ One and RTÉ News Now, also available below on Independent.ie
THE funeral Mass for Gay Byrne heard that his "legacy will live on".
Huge crowds began gathering outside the Pro Cathedral from early this morning to pay their final respects to the late icon.
RTÉ’s Joe Duffy described it as a “very sad day” and one he hoped he would never see.
Ryan Tubridy said that the Late Late show special which aired on Tuesday was like a “national wake” for the people of Ireland who had responded in droves with their own favourite stories of Gay.
“It was about bringing Gay back into the room and reminding people just how extraordinary he was.
“While he’s gone today, the story lives on, the legacy lives on.”
A trio of elderly gentleman who had worked in RTÉ with Gay for 30 years travelled in to pay their final respects to him this morning.
His former producers Billy Wall and Louis Hogan alongside former director of radio Michael Carroll described him as “one of the greats” and said we’ll never see his like again.
RTÉ’s Marty Morissey said he was “like a hero” and someone he had always respected and admired. He said he had even offered him critiques during his time on Dancing With the Stars and he remained a friend till the end.
Shortly after 11am a group of well-known RTÉ stars arrived en masse, flanked by RTÉ director general Dee Forbes.
Dave Fanning, Ray D’Arcy and wife Jenny and Miriam O’Callaghan were all in attendance alongside former RTÉ director general Cathal Goan.
Miriam told Independent.ie: “It’s a really sad day as we prepare to say our final goodbye to the greatest broadcaster in the world. His brilliance, kindness and all round goodness and decency will never be forgotten. I will miss him greatly. His final act of genius was to ensure that it’s a beautiful day for his final farewell.”
An Taoiseach Leo Varadkar arrived shortly after 11.30am while the President Michael D Higgins came a few minutes later.
Shaking hands with Archbishop Diarmuid Martin, he then walked up and signed the book of condolences.
Other attendees included Claire Byrne, Frank McNamara and Theresa Lowe, former President Mary McAleese and Fianna Fáil leader Michael Martin.
The hearse arrived down Marlborough Street shortly after 12 noon as spontaneous applause broke out among the huge crowds gathered to show their affection for the man who was a national treasure.
Accompanied by four black cars and a mini-bus, his immediate family arrived into the church as they held onto each other for comfort.
Silence descended on those assembled outside as pallbearers, including Gay's grandson Cian (15), gathered to carry the simple brown coffin inside the church a little after noon for the funeral service.
An Taoiseach Leo Varadkar, President Michael D Higgins and his wife Sabina offered their condolences to Gay's wife Kathleen, daughters Crona and Suzy, and his five grandchildren; Cian, Saoirse and Sadhbh, and Kate and Harry, ahead of the Mass.
The ceremony is led by Fr Leonard Maloney SJ, with Archbishop Diarmuid Martin leading the prayers of final commendation.
Gay's daughter Suzy welcomed the congregation to the Mass for "our darling dad and grandfather".
She thanked Professor John McCaffrey and his team at the Mater hospital who had treated her father for the past three years and also the "unsung heroes" of that time, "the Mater's catering ladies and the gentlemen porters who worked tirelessly for us all".
"To say they brightened our journey would be a gross understatement," she added.
Suzy concluded with the words of the poet Brendan Kennelly, who previously wrote about her father.
"He said: 'You gave us words, ideas, music, song. Often you made us laugh out loud and long. Beneath it all you searched for what was true. Thank you for that. Thank you most of all for being you.'"
Fr Leonard Maloney SJ said, "Those who were closest to Gay knew him as a kind, generous and simple person who would counsel them always to give people the benefit of the doubt because, as he used to say, you never know what they are going through."
He spoke about Gay's radio show and how he often "devoted large segments of his two-hour programme to reading extracts from the moving and often harrowing letters from women from all over Ireland" who had had "sufferings and violations visited upon them" and how he "let their voices be heard".
"He recognised their dignity and he validated their experience. They were precicely the poor to whom Jesus refers in today's gospel, 'Happy are those who hunger and thirst for what is right'."
Former RTÉ Director General Bob Collins gave the Appreciation, describing Gay as "reflective, deep, serious, thoughful, a person of values".
He spoke about Gay leaving TV executives "mesmerized by his talent" at an Emmy event in New York in 1983 when he presented a live Late Late Show from the city with "no autocue and no sense of audience as applause machine" and "brought the studio alive, a wonder to behold and to savour".
The Palestrina Choir also performed during the ceremony.
Before the Mass, the procession route for the funeral cortège began at Gay's home in Howth at 11am, heading towards the coast road and then pass over Annesley Bridge.
After travelling to Amiens Street and over the quays at the Matt Talbot Memorial Bridge, it continued along the south quays before turning right on O'Connell Bridge.
The Mass will be followed by a private burial in St Fintan's Cemetery in Sutton.
RTÉ confirmed the news of the broadcast legend's death in a statement on Monday.
The former Late Late Show presenter had been undergoing treatment for prostate cancer for more than two years.
Born in Dublin in 1934, Gay Byrne grew up on the South Circular Road.
He started work as a newsreader and continuity announcer on Radio Éireann in the late 1950s before moving to Granada Television in Manchester, where he worked on a variety of shows, interviewing acts including The Beatles.
For a time he commuted between Dublin and UK, working for both the BBC and RTÉ, but came back to Ireland full time in the late 1960s as presenter and producer of The Late Late Show. He worked on the programme for 37 years.
While he officially retired in 1999, he continued presenting programmes including The Meaning of Life even after his cancer diagnosis.
Gay is survived by his wife Kathleen, their daughters Crona and Suzy, and their families.
The familiar brassy notes of the theme music. The swooping owl. That booming voice, heralding in dramatic fashion the start of the weekend: "Ladies and gentleman, to whom it concerns..."
Billionaire businessman Richard Branson has recalled how he was caught out by Gay Byrne after he wrote his name on his hand as a reminder during an appearance on the Late Late Show.