The earliest extant works of the Japanese tradition date to the early eighth century, during the first decade of the Nara capital. The Kojiki and Nihon shoki are important for their content, a mix of myth, legend, and history, interspersed with poetry, and for the very different styles in which they were written. Kojiki is divided into three books, the first of which describes an early age of the gods, beginning with heaven and earth coming into existence and ending with accounts of the descent of Ninigi. The second book portrays the origins of rule by legendary sovereigns, starting with Jinmu, and describes the expansion of their realm, following reign-by-reign until that of the fifteenth legendary ruler, Ojin. The third book continues from the sixteenth ruler, Nintoku, to Suiko, whose reign represented the beginning of a new era for eighth-century historians. The Nihon shoki provides historians with a fundamental chronology of events in early Japan, especially for the seventh century.