There was a general belief that while death rates for children and young adults would fall as we learnt to conquer infectious diseases, death rates for the over 65s would never slow. Yet by the end of the twentieth century, the decline in human mortality rates was fastest for those in old age. It was argued that life expectancy would never reach beyond 90 years. Latest figures suggest that this will be breached within 20 years, and that half of those born today in Europe will reach over 100. At what year will a human live longer than Jeanne Louise Calment – who died at 122 years old in 1997? Or will this be the maximum life span of any human being? With life expectancy gains reaching over 2 years with every decade this chapter focuses on how long humans can expect to survive, and asks: why is there a search for extreme longevity and what will be the societal consequences?