Generalization is common to every map and central to the theory and practice of cartography. What may be termed the ‘problem’ of generalization, i.e. how to best preserve essential characteristics in the modelling of space, is therefore an important and recurring theme of research published in The Cartographic Journal. If the first 50 volumes show how advances in technology have shaped the discipline, few topics serve to highlight this so clearly; from the evolution of manual to automated methods of generalization, and from geometrically isolated techniques to object-oriented and multi-scalar approaches.