Literary culture was adopted in Finland during the Middle Ages. The literary languages of Finnish society were Latin, Swedish, and Low German. Finnish-language literary culture gradually built on this foundation. In the Middle Ages, only single words and other short expressions were written in Finnish but gradually longer texts began to be written down as well. By the 1530s and 1540s, Finnish had developed into one of the literary languages of the Kingdom of Sweden’s multilingual society. Over the centuries of the early modern period, the use of written Finnish gradually expanded from institutional translated texts for ecclesiastical and administrative uses to edifying guidebooks and secular broadside ballads. In this volume, the history of written Finnish is explored in depth from its early stages up to the early 19th century. This book explores Old Literary Finnish and early Finnish texts from the diverse viewpoints of 21st century linguistics and textual studies. The topics covered include the medieval roots of literary culture, the cultural contexts and multilingualism of the early modern period, the spread of literary culture, the motives of those in power to publish in Finnish, translation and other modes of textual production, genres and paratexts, intertextuality, methods of literary interaction, orthography and other writing practices, language variation and foreign influences, the morphological and syntactic features characteristic of Old Literary Finnish, and methods of lexical growth. The book ends with a brief literary history of early modern Finnish-language texts. This book can be utilised for research and teaching, and is well suited as a source of general information for those interested in the history of written Finnish and old texts. Due to the book’s breadth of texts and presentation of relevant research, it also encourages further studies on the topic.