Leaving the parental home for the first time is one of the most significant migration decisions in the life course, but relatively little is known about such events in the past. This article uses high-quality longitudinal data on the lifetime residential history of individuals to investigate changes in the age at leaving home both over time and between different groups of the population. The age at which men and women left the parental home fell from the late eighteenth century to the twentieth century, with women usually leaving home earlier than men before the twentieth century. Men were most likely to leave home for employment and women for marriage, and the number of men and women leaving home alone increased over time. In the late eighteenth and early nineteenth centuries, it was quite common for the first move from the parental home to occur with a spouse and children after a period of coresidence with parents. The article sheds new light on an important life course transition and raises questions about the meaning of leaving home.