Why did Hadrian build his wall?
After the Romans invaded southern Britain, they had to defend it. They built roads, so that soldiers could march quickly to deal with trouble. They also built three very large army forts, and lots of smaller camps, for soldiers to live in. At first these forts were built of wood, later they were built of stone.
Scotland was not part of Roman Britain, although in A.D. 84, the Romans won a big battle against the Picts who lived in Scotland. In A.D. 122 the Emperor Hadrian ordered his soldiers to build a wall between Roman Britain and Scotland. The wall ran from Wallsend in the east to Bowness on the Solway Firth. You can still walk along parts of Hadrian's Wall today. In A.D. 140, the Romans added another wall further north. It's called the Antonine Wall.
In the third century A.D. there was fighting along Hadrian's Wall. Emperor Septimius Severus had to come to Britain to fight tribes invading from Scotland. Although his soldiers won the battles, he got sick and died at York in A.D. 211.
Why did the Romans build roads?
Roman soldiers needed to march from one part of the country to another quickly. So the Romans built roads. Roman roads were made from stones, and were better than muddy tracks for travel on foot or in carts. So they made travelling around Britain easier for everyone. You can still see the remains of some Roman roads today.
How did Roman Britain defend itself?
Britain was on the edge of the Roman Empire. People living outside the empire sometimes tried to attack Roman Britain. Some were pirates in ships. The Romans kept a navy to defend Britain. They also built forts on the coast.
Soldiers kept watch at the forts, and fought any enemies who tried to land in Britain. The forts are called Saxon Shore forts, because many of the people attacking Britain at this time were Saxons. The Saxons were people living in north Germany.
The Romans also had to defend Hadrian's Wall, against attacks by Picts and other tribes These people lived in northern Britain, outside the Roman part. Soldiers sent to defend the wall lived in forts and camps.