"The family of Robin Gibb, of the Bee Gees, announce with great sadness that Robin passed away today following his long battle with cancer and intestinal surgery," his family said in a statement after his death Sunday.
Robin, his twin brother Maurice and elder brother Barry, scaled the heights of the pop world in the 1970s with disco hits including "How Deep Is Your Love", "Stayin' Alive", and "Night Fever".
The trio's high-pitched close harmonies, sharp songwriting and disco sounds made them one of the biggest-selling groups of all time, notching up record sales of more than 200 million since their first hits in the 1960s.
Robin mostly sang lead in the 1960s, while Barry's falsetto took the foreground in their 1970s disco period.
Tributes poured in from fellow musicians.
Simply Red frontman Mick Hucknall called him a "musical giant" while DJ Paul Gambaccini said he was "talented beyond even his own understanding".
"Everyone should be aware that the Bee Gees are second only to Lennon and McCartney as the most successful songwriting unit in British popular music," Gambaccini said.
Robin lost his battle against cancer of the colon and the liver just a month after confounding doctors by emerging from a coma after suffering pneumonia.
He underwent surgery in August 2010 for a blocked intestine -- the same condition that killed brother Maurice in 2003 -- but a tumour was found and he was diagnosed with cancer.
The singer looked gaunt in his last few months as he struggled against the relentless disease.
Andy Gibb, their younger brother who was not in the Bee Gees, died in 1988 from cocaine addiction.
"I sometimes wonder if all the tragedies my family has suffered -- like Andy and Maurice dying so young and everything that's happened to me recently -- is a kind of karmic price we are paying for all the fame and fortune we've had," he told The Sun newspaper in March.
Robin's death came just days after the Queen of Disco Donna Summer died from lung cancer in Florida at the age of 63.
Robin enjoyed a musical career spanning six decades, from humble beginnings in the 1950s singing with his brothers in cinemas, to his recent first classical venture, "The Titanic Requiem", penned with his son Robin-John.
But he was too ill to attend the April premiere.
The singer and his wife-to-be Molly Hullis had survived a 1967 rail crash in southeast London that killed 49 people.
"I know what it is to live through a mass disaster... it haunts me to this day," he wrote in The Mail on Sunday newspaper in January.
Robin Hugh Gibb was born on December 22, 1949 on the Isle of Man, the British crown dependency, about half an hour before Maurice.
Soon after, the Gibb family moved to Manchester, northwest England, and then to Brisbane in Australia in 1958.
The Bee Gees soon became child stars and had their first hit in 1963, "The Battle of the Blue and Grey", performed on national television.
"We used to say that we were one soul in three bodies. We worked with such spirit between us, able to read each other's thoughts when we wrote together," Robin once said.
The trio returned to Britain in 1967 where they soon had several more successes, including the UK number one "Massachusetts".
"How Can You Mend a Broken Heart", the group's first US number one, along with "Jive Talkin'", "Nights on Broadway" and "You Should be Dancing" established them as big stars.
But the disco soundtrack "Saturday Night Fever" (1977), which sold more than 40 million copies, was their biggest success, becoming one of the best-selling albums of all time.
The brothers also also wrote hit songs for others including Diana Ross, ("Chain Reaction"), Barbra Streisand ("Woman In Love"), Kenny Rogers and Dolly Parton ("Islands In The Stream") Dione Warwick ("Heartbreaker") and Frankie Valli ("Grease").
Their last studio album was 2001's "This Is Where I Came In".
The Bee Gees were made Commanders in the Order of the British Empire -- one step below a knighthood -- in 2004.
Robin Gibb was a friend of former British prime minister Tony Blair, who was criticised for taking "freebie" breaks with celebrity pals after holidaying at the singer's Miami mansion in 2006.
He appeared on a charity version of "Islands In The Stream" which topped the British charts in 2009, making the Gibbs the first songwriters to pen number UK ones in five successive decades.
He is survived by his second wife Dwina and three children.
