Geographic Information Sciences is a multifaceted science and can be applied to a myriad of industries and applications. For example, GIS is very useful in understanding geospatial relationships with historical events and locations. Hit the hyperlinked quote below for a very good article about its application:
Historical events are increasingly understood within geospatial contexts, where key events, circumstances, and reasons as to why given outcomes occurred are interpreted using GIS. As an example, historical geographyis one area that has applied GIS to understand outcomes of battles, why cities were built in given locations, and using ancient technologies to understand length and difficulty of travel at different times of the year.