Ancient Roman swords were clearly a fundamental element of Ancient Roman weapons and Roman armor. They varied in type and application according to the type of war/engagement and specific age of ancient Rome (we mustn’t forget the Roman empire’s western side lasted approximately a 1000 years whilst the Eastern half lasted through to the Renaissance!
Perhaps the most famous of Roman swords is the Gladius Hispaniensis – as the name suggests this type of sword was actually learned, it is thought, from the Iberian mercenaries hired by the Carthaginians during the Punic wars. This sword could be used both as a cutting as well as stabbing weapon but was at its most deadly when used to stab. Its short length was ideal for close hand-to-hand combat, particularly when used in combination with the large heavy scutum (shield). It was generally used by the three heavily armed infantry known as Hastati, Principes and Triarii.
The Roman cavalry likely used a longer version of the gladius, clearly enabling a better effectiveness with swinging actions from above, or indeed a scimitar type affair also learned from the Iberians which afforded greater weight at the tip.
The light infantry troops known as “Velites” are also thought to have employed the Iberian styled curved sword.