Gladius

A gladius is a Roman short sword mainly used by gladiators and normal soldiers in Ancient Rome. It is Latin for "sword".

Gladius
Replica pseudo-Pompeii gladius
Type	Sword
Place of origin	Ancient Rome, Italy as gladius
Service history
In service	3rd century BC – 3rd century AD
Used by	Roman foot soldiers during wars
Wars	Roman Republic and Roman Empire
Specifications
Mass	0.7–1 kg (1.5–2.2 lb)
Length	60–85 cm (24–33 in)
Blade length	45–68 cm (18–27 in)
Width	5–7 cm (2.0–2.8 in)
Blade type	steel of varying degrees of carbon content, pointed, double-edged
Hilt type	Wood, bronze or ivory

The Roman gladius came from the Celtiberians of Hispania, more specifically a sword used in the Second Punic War. When Rome won the Second Punic War, they adopted the gladius into the Roman army, which they adapted slightly to their needs for a soldier's sword.

After the military reforms of Gaius Marius during his consulships, the roman soldier was armed with a sword (gladius), a shield (scutum), two spears (pila), most of the time a dagger (pugio), and later in roman history, some throwing darts (plumbatae).

Roman soldiers in battle would throw pila to disrupt the enemy and make their shields usless, then go into close hand to hand fighting, in which the gladius was used.

You can read more about gladiators here.