Participial prepositions and conjunctions such as considering, during, considered and except are a comparatively recent phenomenon in the history of the English language. They originated in the intense language contact situation between Anglo-French and Middle English in late medieval England. In this book, it is shown that the development is part of a long process of typological change both in the Romance languages and in the English language. Through language contact a productive pattern has been established in English, which still produces new participial prepositions today (e.g. following, based on and looking at). Participial prepositions and conjunctions therefore clearly illustrate the mechanisms and consequences of language change through intense language contact.