The cult of Maitreya was particularly influential in the 6th and 7th centuries of the Three Kingdoms period. Sillan kings styled themselves as rulers of a Buddha land, the King symbolizing the Buddha. This religious adaptation is also exemplified in the Hwarang corp, a group of aristocratic youth who were groomed for leadership in the endless wars on the peninsula. The leader of the Hwarang was believed to be the incarnation of Maitreya, a uniquely Korean adaptation of the religion. Maitreya, it was believed, would ascend to earth as the future Buddha in 56 million years and this believe was incorporated into Silla's desire to unite the peninsula. Japanese records also suggest that Sillan images given to the Sillan Hata Clan are the current Koryo-ji Miroku Bosatsu and the Naki Miroku. The Koryu-ji Miroku, dated to 620–640, is stylistically a Korean image, is made from red pine which is indigenous to Korea, and the technique of carving inward from a single log is a believed to be an ancient Korean wood-working technique. The Korean cult of Maitreya, and the major influence of Korean-style pensive images on Japan in the Asuka period. Korean influence on Japanese Buddhist art was very strong during 552–710.