The world's first test-tube baby, Louise Brown, has led the tributes to the pioneer of IVF, who has died aged 87.
Prof Sir Robert Edwards was knighted in 2011, five decades after he began experimenting with IVF.
His work led to the birth of Ms Brown at Oldham General Hospital in 1978. She said he had brought "happiness and joy" to millions of people.
IVF is used worldwide and has resulted in more than five million babies.
Prof Edwards died in his sleep after a long illness.
Ms Brown said: "I have always regarded Robert Edwards as like a grandfather to me.
"His work, along with Patrick Steptoe, has brought happiness and joy to millions of people all over the world by enabling them to have children.
"I am glad that he lived long enough to be recognised with a Nobel prize for his work, and his legacy will live on with all the IVF work being carried out throughout the world."
The University of Cambridge, where Prof Edwards was a fellow, said his work "had an immense impact".
Born in Yorkshire in 1925 into a working-class family, Prof Edwards served in the British army during World War II before returning home to study first agricultural sciences and then animal genetics.
Building on earlier research, which showed that egg cells from rabbits could be fertilised in test tubes when sperm was added, Edwards developed the same technique for humans.
In a laboratory at Cambridge in 1968, he first saw life created outside the womb in the form of a human blastocyst, an embryo that has developed for five to six days after fertilisation.
"I'll never forget the day I looked down the microscope and saw something funny in the cultures," Edwards once recalled.
"I looked down the microscope and what I saw was a human blastocyst gazing up at me. I thought, 'We've done it'."
"Bob Edwards is one of our greatest scientists," said Mike Macnamee, chief executive of Bourn Hall, the IVF clinic founded by Prof Edwards with his fellow IVF pioneer Patrick Steptoe, a gynaecological surgeon.
Prof Martin Johnson, one of his first students, said: "Bob Edwards was a remarkable man who changed the lives of so many people.
"He was not only a visionary in his science but also in his communication to the wider public about matters scientific, in which he was a great pioneer.
"He will be greatly missed by his colleagues, students, his family and all the many people he has helped to have children."
Prof Peter Braude, Emeritus Professor of Obstetrics and Gynaecology at King's College London, said: "Few biologists have so positively and practically impacted on humankind.
"Bob's boundless energy, his innovative ideas, and his resilience despite the relentless criticism by naysayers, changed the lives of millions of ordinary people who now rejoice in the gift of their own child."
Edwards was too frail to pick up his Nobel prize in Stockholm in 2010, leaving that job to his wife Ruth, with whom he had five daughters.
He remained a fellow of Churchill College, Cambridge, until his death.
His work was motivated by his belief, as he once described it, that "the most important thing in life is having a child."
"Nothing is more special than a child," he said.