The scientist who pioneered the development of test tube babies, Professor Sir Robert Edwards, has died at the age of 87.
Professor Edwards began developing in-vitro fertilisation (IVF) in 1955. More than 5 million babies have been born around the world as a result of the techniques he developed along with his late colleague Patrick Steptoe.
Born in Yorkshire in 1925, Professor Edwards served in the British army during World War II before returning home to study first agricultural sciences and then animal genetics, the BBC reports.
Building on earlier research, which showed that egg cells from rabbits could be fertilised in test tubes when sperm was added, he developed the same technique for humans.
In a laboratory at Cambridge in 1968, Professor Edwards 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.
His work led to the birth of the first test tube baby, Louise Brown, in Britain in 1978.
Ms Brown led the tributes to Professor Edwards, who she said had brought happiness to millions of people.
"I have always regarded Robert Edwards as like a grandfather to me," she said. "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.
The University of Cambridge, where Prof Edwards was a fellow, said his work "had an immense impact".
His work was motivated by his belief, as he once described it, that "the most important thing in life is having a child."
Prof Edwards died in his sleep after a long illness.