Topic: Tell me a short, interesting fact about

The Roman Empire reached its largest territorial extent in AD 117, during the reign of Emperor Trajan, stretching from Scotland in the north to Mesopotamia in the east, and from Armenia in the north to as far as the Sahara Desert in the south. This vast territory was once referred to as "Orbis Terrarum Romanarum," or the Roman World. In an attempt to account for the exchequer of the empire's far-flung territories, Trajan even had a coin made with the inscription "Plus Ultra" – Latin for "Beyond the Pillars of Hercules" (a reference to the Pillars of Hercules, the landmarks marking the westernmost point of the safely navigable Mediterranean) – followed by a simple but significant "Non Plus Ultra" ("No Further West"), signifying that Rome had reached the edge of the world according to ancient understanding. This coin symbolizes Rome's ambition, influence, and territorial expansion at its zenith.