Soroku was a position that existed in Japan following the middle ages responsible for religious human affairs such as the registration and appointment of head priests
According to the writing 'Zuoyou Jieseng Lue' within "Dasong Sengshi Lue" by Zanning, an early Northern Song Dynasty soroku responsible for the right side of the city, the position originated in China during the Yuanhe era of the Tang Dynasty. Priest Duanfu is considered to have been the first to have held the post. It is said that the position of soroku responsible for the both sides of the city was created during the reign of Emperor Wenzong (Tang Dynasty).
In Japan, Takauji ASHIKAGA unified Zen Buddhism (Rinzai Sect and Soto Sect) and Ritsu Buddhism (including the Shingon Ritsu Sect) in 1336, and the position of Zenritsugata (overseer of Zen and Ritsu monasteries) was created, which was held by Kazuuji HOSOKAWA, FUJIWARA no Arinori (Fujiwara Nanke family), Ujiyori SASAKI and Norisuke AKAMATSU. This became a formal institution of the Muromachi bakufu (Japanese feudal government headed by a shogun), and it was decided by Yoshimitsu ASHIKAGA that the position would be called 'Sorokushi,' being first held by Shunoku Myoha of the Gozan (five highest ranked Zen temples). As the connection between the bakufu and Gozan strengthened, the post of soroku came to be monopolized by Gozan monks who controlled all temples under control of the Gozan as the highest institution of the Rinzai Sect.
When Zekkai Chushin of the Rokuon-in sub-temple of Shokoku-ji Temple was appointed soroku, the grave of Yoshimitsu was placed within the temple grounds and it came to be that the head priest of this temple also served as soroku, being called 'Rokuon Soroku.'
Rokuon Soroku determined the ranks of and appointed head priests to all temples below the Gozan as well as managing territory and litigation, so had a great degree of influence even when compared to the bakufu, but the position later developed into an honorary position with individuals being appointed based on blood relationships to the Imperial Family and actual responsibility being taken by the inryoshiki who served as a liaison between the sofoku and the bakufu.
In 1615 after the establishment of the Edo bakufu, Shoshu Jin Shohatto (law decreeing rules for Buddhist temples) was enacted and the posts of soroku and inryoshiki were abolished, with the bakufu attempting to exert direct control. However, Ishin Suden was appointed soroku by the shogunate four years later.
It later came to be that the head priest of the Konchi-in sub-temple of Nanzen-ji Temple at which Suden resided assumed the position of soroku, being called 'Konji-in Soroku.'
There were also sects other than the Rinzai Sect such as the Soto Sect Kansansatsu (three main temples of Soto Sect) which also had the position of soroku.