Complex sentence: The Nationalists prior to the Japanese invasion, notably Sukarno and Mohammad Yamin, often cited Gajah Mada's oath and Nagarakretagama as the inspiration and a historical proof of Indonesian past greatness--that Indonesians could unite, despite vast territory and various cultures.
Split into simpler sentences: The Nationalists prior to the Japanese invasion, notably Sukarno, often cited Gajah Mada and his oath as an inspiration and a historical proof of Indonesian past greatness. That Indonesians could unite, despite vast territory and various cultures.