On March 5, 1463, the relics of holy Prince Theodore and his sons, David and Constantine were uncovered at Yaroslavl . The chronicler, an eyewitness to the event, wrote: "At the city of Yaroslavl in the monastery of the Holy Savior they unearthed three Great Princes: Prince Theodore Rostislavich and his sons David and Constantine, and brought them above the ground. The Great Prince Theodore was a man of great stature, and they placed his sons David and Constantine beside him. They were shorter than he was. All three had lain in a single grave."
The physical appearance of the holy prince so impressed the eyewitnesses and those present at the uncovering of the relics, that an account of this event was entered into the Prologue (lives of saints) in St Theodore's Life, and also into the text of the Manual for Iconographers.
Sts Theodore, David and Constantine are also commemorated on September 19. SOURCE: