Br Symeon Gillette was born in 1949 in Hicksville, NY into a family of six children and was given the name Michael. He studied in high school with the Marist Brothers and majored in art at the State University of New York at Stony Brook. After working for six years as an insurance underwriter he entered the St. Louis Priory in 1977 and after discovering the medieval writer Symeon the New Theologian, took the religious name Symeon. He made simple vows in 1979 and solemn vows in 1982. He studied horticulture at Meramec Community College and was responsible for planting many trees on the Priory Campus.
After profession Br Symeon became a faculty member of the Saint Louis Priory School, teaching classes over the years in mechanical drawing, calligraphy, the painting of medieval banners, icon writing and mosaics. But his signature achievement was his work in stained glass and his teaching of the making of stained glass in the years around the millennium. He won the affection of his students with whom he created a guild of medieval arts, which resulted in large-scale projects now installed in the Priory School and Saint Louis Abbey, including a large Millennial Window (2000) and a Jubilee Window (2005) commemorating the 50th anniversary of the arrival of the founding monks of Saint Louis Priory, now Abbey. Students came to value his modeling of patience, precision, and self-confidence.
In his last years he delighted in baking new recipes of bread for the monastic community. His love for God was manifest in his spiritual arts, in his love for his students, and in a seven-year period of living as a hermit on the Abbey campus. Br Symeon died suddenly at the Abbey on November 9. A funeral Mass and burial were celebrated at the Abbey on November 15. May God reward him.