We are not all born with equal opportunities. Yet there have been countless women who have overcome a range of barriers such as prejudice, illness, and personal tragedy to advance our understanding of science, technology, engineering, and mathematics (STEM). They used their knowledge to change the world, and their stories are fascinating. This book offers a concise introduction to the lives of 45 women, taking you into the cultural and social context of the world they lived in. Through their intelligence, courage, and resilience, they used STEM to defy expectations and inspire generations to follow in their footsteps. Some of them invented items we use day-to-day and discovered causes and treatments for epidemics that ostracised whole sections of society, whilst others campaigned for the reproductive rights of women and harnessed mathematics to send people into space and break ciphers. These women are proof that females can and did have a hugely significant role in shaping the world we live in today.