Youth culture is not an invention of twentieth-century movies and television; youth have been forming their own cultures from the moment they were given space to invent their own ways of relating to one another and to their parents and communities. Taking a global approach and beginning in early modern Europe, the essays in the Oxford Handbook of the History of Youth Culture provide broadly contextualized case studies exploring how the meanings and expressions of both "youth" and "culture" have developed. The authors show that youth culture has been shaped by geography, ethnicity, class, gender, faith, technology, and myriad other factors. Throughout, authors emphasize the ways in which the idea of youth culture could become contested terrain -- between youth and their families, their communities, and the culture at large -- as well as the importance of youth agency in carving out separate lives.