Due to the World Wars, Lithuanian science and scientists suffered heavily from the occupants, however some of them reached a world-class achievements in their lifetime. Most notably, Antanas Gustaitis, Vytautas Graičiūnas, Marija Gimbutas, Birutė Galdikas, A. J. Kliorė, Algirdas Julius Greimas, medievalist Jurgis Baltrušaitis, Algirdas Antanas Avižienis.