Louise Brown, the world's first 'test tube baby', has led tributes for IVF pioneer Professor Sir Robert Edwards after his death at the age of 87.
Prof Robert, who received the Nobel prize in 2010, was one of two fertility experts whose work led to Ms Brown's birth on July 25, 1978. His colleague Patrick Steptoe, died in 1988.
Since Ms Brown's arrival, more than five million babies have been conceived and delivered around the world using IVF techniques.
News of Prof Robert's death after a "long illness" was announced on behalf of his family by Cambridge University, where he worked for many years in the department of physiology.
Experts in the fields of fertility lavished praise on his achievements, comparing him with Charles Darwin.
Ms Brown said: "It was really sad to hear the news today. I have always regarded Robert Edwards as like a grandfather to me. His work, along with Patrick Steptoe, has brought joy to millions of people all over the world by enabling them to have children."
He leaves his wife, Ruth, five daughters and 12 grandchildren.