The first time the word 'Shinkoku' appeared was in the "Chronicles of Japan," it was said when Empress Jungu raised an army at 'Sankan Seibatsu' (The Conquest of the Three Korean Kingdoms), the king of Silla (Kingdom) proclaimed 'it was an army from Shinkoku' and surrendered without fighting.
「神国」という言葉の初出は『日本書紀』の神功皇后のいわゆる「三韓征伐」の際、新羅王が皇后の軍勢を見て「神国の兵である」として戦わずに降伏したという記事である。