This database of global wars and conflicts is searchable through space and time. You can drag and click both the map and timeline to locate particular battles and wars, and then read more information about that conflict. This resource would be a great one to show students and let them explore to find what they see as interesting. This site is brimming with potential.
Via Seth Dixon, Martin Daumiller, Sakis Koukouvis, Dr. Stefan Gruenwald