Pugio

The pugio (Plural: Pugiones) was a dagger used by Roman soldiers as a sidearm. It seems likely that the pugio was intended as an auxiliary weapon, but its exact purpose to the soldier remains unknown. Attempts to identify it as a utility knife are misguided as the form of the pugio is not suited to this purpose and in any case utility knives of a variety of sizes are common finds on Roman military sites, meaning there would be no need for a pugio to be used in this way. Officials of the empire took to wearing ornate daggers in the performance of their offices, and some would wear concealed daggers as a defense against contingencies. The dagger was a common weapon of assassination and suicide; for example, the conspirators who stabbed Julius Caesar used pugiones.

Like the gladius, the pugio was probably a stabbing weapon, the type of weapon said to have been preferred by the Romans. Of them, late Roman writer Vegetius, says:

A stroke with the edges, though made with ever so much force, seldom kills, .... On the contrary, a stab, though it penetrates but two inches, is generally fatal. ... the body is covered while a thrust is given, and the adversary receives the point before he sees the sword. This was the method of fighting principally used by the Romans ...

Vegetius may be overstating this point however, as there are a number of surviving Roman depictions of soldiers slashing with their weapons in addition to stabbing with them. This is shown best on the Adamklissi metopes.

The word possibly descends from the Proto-Indo-European root *peuĝ-, "stab, stick." The root is the same as in English pugilist, "boxer." It is still possible to use punch and stab synonymously in many Indo-European languages; hence, Latin pugnus and Greek πυγμή pygmḗ mean "fist." The Smith article cited below proposes that the pugio was the weapon grasped by the fist; however, the Latin word for swordplay was pugna, an exchange of thrusts without the intermediary of fists, although it could also be a fistfight.

Ultimately the pugio was descended from Spanish originals of a variety of types, but by the early 1st century AD the Roman dagger typically had a large blade, which could be 'leaf-shaped' (type 'A') or which might alternatively have narrowed from the shoulders to run parallel to about half the blade's length, before narrowing to a sharp point (type 'B'). In size they ranged from 18 cm to 28 cm (7 in to 11 in) long and 5 cm (2 in) or more in width. A midrib ran close to the length of each side, either standing out from the face (mainly on type 'A' blades) or sunken and defined by grooves on either side (mainly on type 'B' blades). The tang was wide and flat initially, and the grip was riveted through it, as well as through the shoulders of the blade. The pommel expansion was originally round but by the early 1st century AD this was being replaced by a pommel expansion typically of a bulbous, roughly trapezial shape, often topped by three decorative rivets.

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