The Romans were only able to take over Britain because of their powerful Roman Army. They stationed up to 20,000 soldiers in Britain, divided into lots of different units. After the Conquest, the army upheld the law and the rule of the Emperor. They protected the province of Britannia from 'barbarians' in Caledonia (Picts in Scotland) and pirates from Hibernia (Ireland) and Germania (Anglo-Saxons from near Germany). Regular Roman troops fought with short stabbing swords and spears. They had large curved rectangular shields. But there were few wars. Most of the day was spent: drilling marching patrolling guard duty cleaning cooking fuel collection looking after the horses & pack animals The soldiers did lots of other jobs at times though, especially building work.  Roman soldiers were well fed. They mostly lived on bread, soup, meat, vegetables and sour wine or vinegar. They were not allowed to marry, but often had girlfriends and children living near their fort. Soldiers serving in Britannia retired at the age of about 40. They were given land to live on and encouraged to teach people Roman ways. This might be in a type of town called a 'colonia'. They were specially created for army veterans. Troubles back in Rome, led to British commanders taking lots of troops out of Britain in the late 4th century. When the Roman army left, the Roman way of life fell apart.