Abstract: By tracing early European maps as "instruments of knowledge production" within power relations, this study situates Imperial Federation: Map of the World Showing the Extent of the British Empire in 1886 within the dual frameworks of global history and critical cartography. It analyzes how the map constructs specific forms of "knowledge" through selective inclusion and omission of information, the disguise of statistical data, and the symbolic deployment of artistic ornamentation. These epistemic constructions present Britain as extensively occupying overseas territories and sea routes, claiming the right to colonize terra nullius and non-British regions, promoting common prosperity in Britain and its colonial areas through trade, and envisioning a prospect in which all British subjects achieve freedom and peace through mutual cooperation. Such processes of knowledge production contribute to the construction of the myth of "Greater Britain" through the mutual expansion of geographical space and national imagination, while attempting to suture class, gender, ethnic group, and party divisions in the late Victorian society. This analysis demonstrates that British maps functioned as powerful instruments of knowledge production at the end of the 19th century, re-encoding both British society and global relations.