stylite

n. [ Gr. styli`ths, fr. sty^los a pillar. ] (Eccl. Hist.) One of a sect of anchorites in the early church, who lived on the tops of pillars for the exercise of their patience; -- called also pillarist and pillar saint. [ 1913 Webster ]

The two other holy men in Gregory's narrative had more exotic origins than the pair that has just been seen. Gregory encountered one of them when on a journey to the north-eastern parts of the Frankish kingdom. This was a Lombard, named Vulfolaic, who had spent some years in the arduous exercise of being a stylite, the Christian equivalent of a flagpole sitter; in other words, Vulfolaic was a monk whose main austerity consisted in living on top of a pillar. By carrying out this feat in the rain, snow, and frost of the Moselle valley, Vulfolaic had convinced the local population to overthrow and abandon the idol of Diana to which they were addicted. Walter Goffart, FOREIGNERS IN THE HISTORIES OF GREGORY OF TOURS (https://journals.lib.unb.ca/index.php/flor/article/download/15346/20501).