Late Antiquity (3rd–5th century) was a period of profound change. While the 1st and 2nd centuries had been marked by the stability of the Principate, with secure frontiers, a strong economy, and the classical image of the Roman legionary, the 3rd century saw the face of the Empire transformed. New enemies such as the Goths, Franks, and Persians put pressure on the borders, while internal power struggles and economic crises shook the old order.

The army underwent visible changes: the classical legions of the imperial era gave way to a more flexible structure. Smaller units, the so-called comitatenses and limitanei, replaced the large army formations. Equipment also evolved: instead of rectangular shields, round ones became dominant, helmets and armor grew more varied, and soldiers often carried longer swords (spatha). At the same time, new religious movements gained influence, and Christianity spread throughout the Empire.

Late Antiquity was not a “declining” age but a period in which the Roman Empire had to find new answers to a changing world.