President Michael D Higgins, Van Morrison, Ringo Starr, U2, and Sting were among those who paid tribute to Bob Geldof on his 70th birthday on a surprise Late Late Show special dedicated to the singer on Friday night.

A gob-smacked Geldof was taken by surprise on the show when he realised he wasn't just in studio to perform some songs and was instead greeted by members of his family, including daughters Pixie and Tiger, his sister Lynn, and his wife, French actress Jeanne Marine, alongside guests Midge Ure, Imelda May, and Andrea Corr, and many of his friends in the audience.

Bob performing on the Late Late

After performing the 1979 number one hit I Don’t Like Mondays with The Boomtown Rats, Geldof was taken aback when the birthday surprise was revealed.

"Is this some crap This is Your Life s***?" he said, adding, "F***ing hell! This is mortifying."

Asked how he was feeling on his birthday by host Ryan Tubridy, the singer, activist and humanitarian said, "Well, I’m looking forward to decrepitude, impotence, senility . . . that’s down the track. Great! 70! I don’t mind it, I don’t want to be any period earlier, I don’t want to relive anything. But when you say what age are you know and I say I’m 70 . . . F***!!

"When you see that - look at that auld fella. He’s on the way out. I feel fine. Ah! The old knees are at me."

President Higgins sent his birthday greetings in a letter, which Ryan read out. "I’m delighted to send my best wishes to Bob Geldof on a milestone birthday," the President said. "Bob has left a deep imprint on Ireland in his musical voyage.

Bob meets some old friends on the Late Late

"He has demonstrated limitless empathy. A man whose life who has been rooted in a tireless and profound sense of shared humanity. May I join with all those others, his family, friends and many fans and admirers across the world in wishing him a very happy 70th birthday. An appropriate age to up the tempo."

Reacting to the letter, Bob said, "As you age, time telescopes and it’s pretty mad that you’re in Dun Laoighaire one second and feeling empty and lost and the next thing you’re sitting on a chair on national TV and the President of Ireland writes you a letter."

Pointing to the numerous pictures of her husband at various stages of his career which adorned Studio 4 in RTÉ, Jeanne Marine said, "I am amazed at how sexy and beautiful all these pictures are and I have to say the version of 70 is not too bad at all."

Midge Ure, who befriended Bob in the late seventies when he was in The Rich Kids and Geldof was starting out in the Rats, said of his friend, "It was a match made in heaven. I get goofy Bob. I get to see Bob when the cameras are off. He’s highly intelligent, very well read but I get to see Bob as a mate.

"I was reasonably unscathed by Live Aid. I was able to go out and do what I do and get back out performing with Ultravox and I was doing a solo show at Wembley and a big bunch of flowers turned up backstage with a little handwritten note from Bob saying, `You lucky bastard. I wish I was you’.

"Now this is from a guy who was seen as a leader and a spokesman for youth, as a quasi-politician, one of the most famous people in the world and all he wanted to do was go out and perform."

Geldof and the Rats also performed their songs Rat Trap, Banana Republic, and Nick Lowe’s Peace Love and Understanding on the show, a track that Geldof said had a special meaning to him.

There were special contributions from around the world from Ringo Starr, Roger Waters and Van Morrison.

Speaking in a video message, Elton John said, "Those 70 years represent a legacy of great music and much more. You literally changed the way the world saw catastrophe and need."

Van Morrison sent his greetings from San Francisco Bay, while former British Prime Minister Tony Blair said what Bob Geldof has done for Africa and its people and what he continues to do for the world is immense.

"It's measured in the best currency politics knows which is lives changed for the better," Blair said in a video message.

While former president Mary Robinson said Geldof has been a serious adviser for Africa and often hears his name mentioned which great respect and gratitude.

"I really honour what you've done," she said.

Alan Corr @CorrAlan