GUICHARD, KARL GOTTLIEB soldier and military writer, known as QUINTUS IcILrass, was born at Magdeburg in 1724, of a family of French refugees. He was educated for the Church, but sought and obtained a commission in the Dutch army, making the campaigns of 1747-48 in the Low Countries. In 1757 his Memoires militaires sur les Grecs et les Romains appeared at the Hague; and in Jan. 1758 he entered the service of Frederick the Great, remaining for nearly 18 months in the royal suite. Guichard's Prussian official name of Quintus Icilius was the outcome of a friendly dispute with the king (see Nikolai, Anekdoten, vi. 129-145; Carlyle, Frederick the Great, viii. 113-114). He was appointed to the command of a free battalion. This corps he commanded throughout the later stages of the Seven Years' War, his battalion, as time went on, becom ing a regiment of three battalions, and Quintus himself recruited seven more battalions of the same kind of troops. His command was almost always with the king's own army in these campaigns, but for a short time it fought in the western theatre under Prince Henry. When not on the march he was always at the royal head quarters, and it was he who brought about the famous interview between the king and Gellert (see Carlyle, Frederick the Great, ix. 109 ; Gellert, Brie f wechsel mit Demoiselle Lucius, ed. Ebert, Leipzig, 1823, pp. 629-631) on the subject of national German literature. He was made lieutenant-colonel in 1765, and in in recognition of his work Memoires critiques et historiques sur plusieurs points d'antiquites militaires, dealing mainly with Caesar's campaigns in Spain (Berlin, 1773), was promoted colonel. He died at Berlin on May