What was the role of Roman fortifications in the empire's defense?

Roman fortifications played a crucial role in the defense of the Roman Empire. The Roman army used a variety of fortifications, including walls, towers, and forts, to protect their territories from invading armies and marauding tribes.

The most famous Roman fortifications were the walls built to protect the city of Rome itself. The Servian Wall, built in the fourth century BCE, was the first wall to surround the entire city. Later, the Aurelian Wall, built in the third century CE, was even more impressive, stretching for over 12 miles and incorporating 18 gates.

Outside of Rome, the Roman army built a network of fortifications across the empire to protect its borders from invasion. The most famous of these fortifications was Hadrian's Wall, which was built in the second century CE to protect the northern border of the Roman province of Britannia. The wall stretched for 73 miles and included forts, milecastles, and turrets.

Roman fortifications also played a role in maintaining order within the empire. Forts were often built in strategic locations to control access to important resources, such as mines and rivers, and to act as bases for Roman military operations. Fortifications were also used to control the movement of people and goods within the empire, as well as to defend against piracy and banditry.