Saigyō is a Japanese poet of the Heian and Kamakura periods, one of the best known and most popular creators of tanka poetry. Sato Norikyo was born into a noble family in Kyoto. After the beginning of the Mappo era, Buddhism was thought to have fallen into decline and was no longer an effective means of salvation. These cultural shifts in the author's lifetime led to a sense of melancholy in his poetry. As a young man he worked as a guard for the retired emperor Toba, but in 1140, at the age of 22, for reasons unknown today, he left the worldly life and became a monk, taking the religious name En'i. He was a good friend of Fujiwara no Teika. Sankashū ("Collection of the Mountain House") is Saigyō's personal poetry collection. Other collections that include Saigyo's poems are Shin kokin wakashu and Sika wakashu. He died at Hirokawa Shrine in Kawachi Province (present-day Osaka Prefecture) at the age of 72.