This introductory chapter outlines the central and inextricably linked avenues of research covered in this edited volume. Contributions to the edited volume root themselves in the World Englishes paradigm and explore (short-term) diachronic and/or regional patterns of variation in first-and second-language varieties of English. To conduct said analyses, often only recently compiled corpora are employed to delineate formerly unseen systematicities across African, Asian, and Caribbean Englishes that habitually result from long-lasting language contact. Yet, this volume also expands the relatively young research strand exploring register variation within and across different World Englishes through the analysis of novel datasets representing, on the one hand, specialised registers such as ornithological discourse, and, on the other, the ways in which structural characteristics of regional varieties are employed in such specialised registers. The introduction ends with short summaries of the contributions in this edited volume.