As more and more efforts are made to preserve cultural heritage all over the world and more and more print material — old newspapers, books, documents or posters — is being digitised and made available online, language units can be studied diachronically with “distant reading” on various levels of analysis. This book aims to present the theory and practice of mining Polish language units, such as words, collocations, names and folk-tales from massive diachronic corpora. The book takes a bottom-up approach, starting from the issues related to handling large diachronic collections and searching in them, whereas the third part focuses on the techniques used to model the Polish language along the time dimension. Finally, the apparatus developed in the book is applied in the context of specific types of linguistic, folkloristic and historical research. The author draws on the ideas of “culturomics” (studying the culture through the lens of diachronic corpora), though their limitations are exposed in the book.