This volume focuses on the nature of official correspondence produced in the period after 1500, from Early Modern to nineteenth-century English. The contributions reflect the extent to which the genre is somewhat plastic in this period, gradually acquiring distinguishing conventions and protocols as the situations in which the letters themselves are encoded acquire more distinctiveness. Although correspondence has long been the object of diachronic studies, very little seems to be available as far as specialized usage is concerned, hence the specific interest in letters exchanged within scientific, diplomatic, and business networks. In addition, the study of business and official correspondence offered here profits from a multi-disciplinary and multi-methodological approach, as it relies on a rich array of databases and corpora of correspondence, ranging from highly specialized collections to more broadly constructed diagnostic corpora, in which correspondence is just one register or text-type. While specific attention is paid to phenomena relating to the expression of positive and negative politeness through the investigation of authentic (rather than constructed) texts, methodological issues are also taken into consideration.