On 3 December 1967, in the Groote Schuur Hospital of Cape Town, Dr Christiaan Barnard took his scalpel and carved his name into the scientific hall of fame.
The South African cardiac surgeon wanted to try something that had never been done: replacing a man's dying heart with a healthy one.
His patient was 54-year-old Louis Washkansky, a grocer from Cape Town. Before his operation, Washkansky had suffered three heart attacks. He was diabetic and several doctors - including Barnard himself - told him there was nothing they could do.
By the time he was admitted to the Groote Schuur Hospital in September 1967, only a third of his heart was still functioning.
But Barnard, who had experimented on animals in the Groote Schuur Hospital labs, proposed to Washkansky that he attempt a transplant. The patient agreed. All they needed was a donor.
Washkansky should have received the heart of a young black man at the end of November 1967. But things were not so simple in South Africa under Apartheid. The Chief of Cardiology, Val Schrire, opposed giving a black man's heart to a white man. The police still asked the man's family for permission for him to be a heart donor. However, a slight irregularity on his cardiographs gave Schrire another reason to oppose the transplant.
Washkansky finally found his donor in 25 year old Denise Darvall. She had been declared brain dead after a car accident on 2 December. Her father agreed to donate her heart and kidneys.
The operation started at midnight and lasted for six hours. Washkansky's new heart received an electrical shot and... voila! It started beating again.
After waking up from the operation, the man was able to talk with his wife and to occasionally walk.
However, the story didn't have a happy ending for Washkansky. His condition deteriorated and he died of pneumonia 18 days after the operation.
For Barnard, it was the beginning of a long list of heart transplants. Washkansky's case brought him international fame - as well as a few people accusing him of playing God and hate mail calling him a butcher.
But in the 50 years since the first ground-breaking operation, tens of thousands of people have been given the gift of life thanks to Dr Barnard .