This chapter chronologically traces past legal engagement with the human embryo, from the 13th century, to the end of the 20th century. It does so with a view to demonstrating that a historical perspective is required to understand that process is a key facet of law-making in this area. Notable from this legal history is the law’s persistent efforts to engage with the embryo’s uncertain, processual nature. We cannot fully understand our present legal position without understanding the social, moral, and legal context from which it was born. By looking at the past ‘legal embryo,’ we can see how the law has reached today’s ‘legal embryo’.