The Roman Empire’s expanse was legendary – huge and sprawling expanse. But even the Romans knew their limits. Let’s look at the furthest extent of the Roman Empire and how the Romans defended their borders, which often remained quite porous and amorphous. From natural formations – rivers, mountains, deserts and artificially constructed limits and buffer kingdom zones, let’s examine the fringes of the Roman Empire, constantly changing. From Britain to North Africa, along the Danube, to the Middle East, we’ll examine each challenge that Rome faced in securing its borders.