Robert de Clari (or Cléry, the modern name of the place, on the commune of Pernois) was a knight from Picardy. He participated in the Fourth Crusade with his lord, Count Peter of Amiens, and his brother, Aleaumes, and left a chronicle of the events in Old Picard, De la Conquête de Constantinople. Robert's account of the crusade is especially valuable because of his status as a lower vassal; most other eyewitness accounts are from the leadership of the crusade, like Villehardouin. Robert's descriptions often shed light on some of the crusader activities that are otherwise glossed over by the higher rank sources. Source: Wikipedia (en)