Tracing the history of the Knights Templar, the medieval military and monastic order founded in the early 12th century in the wake of the First Crusade. The Templars flourished under papal protection for almost 200 years, but were dissolved in 1312 by Pope Clement V after they ran afoul of the king of France. The hour also addresses speculation that the order operated later as a secret society, an idea that gained attention in recent years as a result of the popularity of “The Da Vinci Code.”