The First World War (1977)

(From the box description :)

The first game-module to employ SPI's War in Europe maps. Depicts the titanic struggle which ultimately encompassed all of the major powers of the period.
The First World War is a division/corps level simulation of the first time the world went to war. Each game turn represents ten days of real time. Two thousand die cut counters represent the British, French, German, Austro-Hungarian, Russian, Belgian, Turkish, Serbian, Rumanian, Bulgarian, Greek, Dutch, and Italian troops that fought or could have fought in the war - and of course a comprehensive rules booklet and charts are also included.

Rules contain instructions for converting War In Europe maps for First World War use.