Hyginus, pseudo, de Metatione Castrorum (ca 200 – 212 CE)
A military geometer of good theoretical training and practical experience (§45, 47), who
wrote probably in the beginning of the 3rd c. CE, but not later than 212 (edict of Caracalla:
Grillone 1987: 407–411). De metatione castrorum is a more suitable title than the commonly-
accepted de munitionibus castrorum, proposed by a copyist: the author treats fortifications only
briefly at the end (§ 48 – 58), where however he expends no small attention on geometrical
matters, coxae and clauiculae (§ 54 – 55). Coxae round and thus strengthen the angles of the
castra; clauiculae form a vertical quarter-cylinder, extending from the door’s right jamb until
the point corresponding to the central point of the opening part of the wall reserved to the
door (width = 60 feet: §14,49; Grillone 2000: 378–379). Clauiculae and small fossae (§50: titula)
aim to impede frontal attacks, to defend retreating soldiers, and to allow defenders to hit
assailants everywhere.
The rest of the booklet (§ 1 – 47), mutilated at the beginning, addresses only metatio,
i.e., how a camp’s surface is distributed between the units of an army of three legions
in three parts, to the front (praetentura), in the middle (latera praetorii), to the back (retentura);
cohortes partly are symmetrically disposed along the four sides of the castra (8+8 on left
and right hand [§36], 4+4 to the front and to the back [§44]: Grillone 1984: n. 25), partly
in praetentura and in latera praetorii (4+2; §3,9; Grillone 1984: n. 24). In calculating the
area necessary for any unit, the geometer allots 1^1 / 5 foot for each infantryman, and
three feet for each horseman (width fixed at 30 feet for arms, animals.. .; §1). Cohortes
legionariae and other units – auxiliarii and gentes (nationes and symmachares) – differ in that
cohortes legionariae take up quarters according to a fixed plan, also if they have less than
600 soldiers (720×30 feet: § 1 – 2), while other troops have an area corresponding to
the number of soldiers (i.e., cohors peditata: 600 men = 720×30 feet: § 27 – 28), and some-
times the usable area accords to the circumstances (for gentes, if they are less or more
people: §40).
Ed.: Antonino Grillone, Hygini qui dicitur de metatione castrorum liber (1977); M. Lenoir, Pseudo-Hygin, Des
fortifications du camp (CUF 1979).
Antonino Grillone rev. of Lenoir, in: Gnomon 56 (1984) 15–26; Idem, “Problemi tecnici e datazione del
de metatione castrorum dello ps.-Igino,” Latomus 46 (1987) 399–412; Idem, “Soluzioni tecniche
e linguaggio di un geometra militare del III secolo: lo pseudo-Igino,” in Atti del IV Seminario
Internazionale di studi sulla letteratura scientifica e tecnica greca e latina (Messina 29–31 ottobre 1997)
(2000) 365–395; Idem, “Lessico ed espressioni della gromatica militare dello ps. Igino,” in Atti del
Plan view of Clauicula and plan view of Coxa © Grillone
HYGINUS, PSEUDO, DE METATIONE CASTRORUM