The spontaneous overflow of emotions and ideas in the period of European Romanticism did not result only in those works of poetry, drama and fiction that subsequently established themselves in the critical canon: the Romantics also experimented with a great variety of informal modes, including notebook jottings, diaries, letters, travel journals, marginalia in books, and draft reminiscences. As the wide-ranging contributions to this volume demonstrate, such texts offer intimate glimpses of their authors, of literary and personal relationships, and of the evolution of philosophical debates. Frequently drawing on new editorial scholarship in the period, the contributions to this volume collectively illuminate one of the most enticing yet hitherto least appreciated aspects of Romanticism: its informality.