Theodore Trichinas

Saint Theodore Trichinas ("Hair-Shirt Wearer") was born into a wealthy yet pious family in Constantinople . He denounced all earthly and material riches and dedicated his life to Christ in a monastery in the Imperial City. Having given away all that he had to the poor, and himself not owning anything, he clothed himself not in clothes but a rough hair garment all his life, and hence his name. He reposed at the end of the fourth or early fifth centuries. His memory is celebrated on April 20 .

Source: OrthodoxWiki