One of the most remarkable examples of religious self-denial, the stylites were a group of early Christian ascetics who spent long periods of time sitting or standing on top of narrow pillars. (The word comes from the Greek stylos for a column.)
The best known of these pillar hermits, pillar saints or pillar monks was the first, St Simeon Stylites, who sat for thirty years from AD423 onwards on top of a column some 40 cubits high (a cubit was an ancient measure of length, approximately the length of a forearm, say 18 inches or 44 cm). He was followed by several others, including his disciple St Daniel Stylites and Simeon the Younger.
The stylite sometimes allowed himself a roof or a small hut for protection against the weather, but was otherwise exposed. Many remained standing day and night, only prevented from falling by a guard rail; some even stood on one leg.
The record for stylitic behaviour is probably held by the sixth-century St Alypius, who is reputed to have remained on his pillar for 67 years without a break, for the last fourteen of them lying down because his feet could no longer support him. The practice died out shortly after the turn of the last millennium.