The Life of Symeon of the Wondrous Mountain

Simeon Stylites the Younger was an ascetic monk and reputed mystic
(eventually elevated to sainthood) who ran a monastery, spent a lot of time living on top of a pillar, and reportedly saw visions of the future.
He lived in the 6th century CE.
Hagiographical (i.e. biographies of a "saint")
books were written about his life.