The appearance of Vol. 4, Issue 3, 2018 coincides with the very month in which one hundred years ago the fighting of World War I ended in November 1918. The scope of this Issue is taken from the English proverb that necessity is the mother of invention, meaning that needs are a powerful driving force of progress. Modern warfare, most notably the stalemate of the trenches and the arrival of aviation with its airborne surveys, demanded and received response from the cartography departments of the Allied and Central powers. In that respect the war, which was fought mainly but not exclusively in Europe and the Near East, certainly can be seen as an indeed terrible mother of invention, judging by the hitherto unimaginable scope of casualties and destruction for combatants and civilians alike, contributed to, in no small way, by the wartime progress of surveying and cartography. Therefore, thanks to the editors of the International Journal of Cartography, Anne Ruas and Bill Cartwright, this issue embraces their suggestion to mark the centennial with this themed Issue to the 'Great War' (Figure 1), as contemporaries called the conflict of all major powers of these days until the even more destructive World War II came upon them. This themed Issue in some way is a capstone of recent activities by the ICA Commission on the History of Cartography (https://history.icaci.org/) on military cartography with an emphasis on World War I. This focus was inaugurated four years ago by the Commission's 5th International Symposium (Liebenberg, Demhardt, & Vervust, 2016) held in December 2014 in Ghent (Belgium), where there a hundred years ago on the fields of Flanders the attempted German 'blitz' turned into the long trench war of attrition. When setting out on the project of this themed issue, the intention was to provide a comparative investigation of the diverse national approaches to wartime cartography on how the first truly global and industrialized war helped the development of new ways to capture survey data, speed up processing, as well as printing. That emphasis deliberately excluded maps on diplomacy and propaganda, which usually dominate the cartography of World War I imagination. In putting the Issue together, it soon became clear that in tracing the history of the wartime cartographies the international cast of authors reflects on the different directions and depths of hitherto research they were able to draw on. While for the western Allies a lot of original cartographic material and archival records survived and sustained numerous publications, the map historians of the Central Powers are fighting an uphill battle, to stay in military terms. Unlike the United Kingdom, France and the United States, most of the wartime cartography of Germany, Austro-Hungary and Russia, literally, was either dumped by the defeated armies or got lost during World War II. Moreover, there was little appetite amongst these 'losers' to pass on the cartographic stories of a lost cause. Evidently, the cartography of the battlefields was not conc...