Hadrian's Wall: A horde of ancient treasures make for a compelling new Cumbrian exhibition

The Roman Emperor Hadrian, who came to the throne AD117, claimed that the gods had instructed him to "keep intact the Empire", so he planned a massive wall to defend its northern boundary against the unruly tribes beyond. Building was carried out by Roman legionaries; they began while he was visiting Britannia AD122, and finished within six years. Hadrian's Wall is the largest Roman artefact anywhere; it runs a total of 73 miles from Bowness, near Carlisle, in the west to Newcastle in the east. There were turrets and milecastles for defence and signalling, and 16 full-sized forts, including Housesteads near the middle and Birdoswald (originally Banna) closer to Carlisle.

The east end of the wall was constructed of stone blocks, cut from nearby outcrops and quarries. But west of the river Irthing the rocks were harder to find and the wall was originally built of turf; at Birdoswald both the turf original and the later stone wall can be seen side by side, since the stone wall was built 50 metres further north, in line with the fort's northern wall.

The fort at Birdoswald was occupied by troops from AD122 until around AD400, when they all packed up and went home. It was then taken over for about 100 years by locals, probably descendants of the soldiers. In practice, these soldiers were not all Romans; there is evidence from both ends of the wall that some of them came from North Africa and even from what is now Syria; multi-cultural immigration was a fact of life even 1,800 years ago. In particular, a tombstone ploughed up near Birdoswald in 1961 has the inscription: "Sacred to the Spirits of the Departed. Gaius Cossutius Saturninus, from Hippo Regius, soldier in the sixth Legion Victrix Pia Fidelis." The three names show he was a Roman citizen; Hippo Regius was a Roman city in what is now Algeria.

This tombstone is just one of the objects from the new Roman Frontier Gallery at Tullie House Museum and Art Gallery, which tells the story of the 400-year occupation of Birdoswald and other castles on the western end of Hadrian's Wall. The new displays will give a sense of the massive scale of the Roman Empire and all the connections and networks that contributed to its efficient organisation. Many of the objects will be on display for the first time.

The new gallery will also show what life must have been like for the people who lived near the wall. The occupying troops were far from home and probably behaved as badly as many soldiers do in such circumstances. The wall must have divided communities, like the Berlin Wall and the Israeli frontier. Sisters who lived a five minutes' walk apart must have been cut off from one another. Hundreds of people could no longer walk to their local market or even into the village. The wall was not merely a line of defence against marauding tribes from further north, but also a series of checkpoints and customs posts – no doubt an excuse for extracting money or payment in kind from the locals.

Meanwhile, the Romans themselves had a pretty good life. They must have suffered from the cold and the wet; hob-nailed sandals gave a good grip for marching, but precious little protection from the weather. On the other hand, they lived in proper stone buildings and ate good food, much of it imported. On display is a label from an amphora (a jar) advertising the fish sauce that the Romans used in much of their cooking: "Old Tangiers tunny relish, 'provisions quality', excellent, top-quality...." That is reminiscent of: "HP Brown Sauce's unique blend of spices can really add an oomph of flavour to any dish."

The Romans were extremely well organised. They kept the peace (more or less) throughout their vast Empire for 400 years. Since the Empire fell apart there has been fighting somewhere within the region. The Romans were not great innovators; what they did was take many ideas from the Greeks and put them to work with great efficiency. They used Greek-inspired surveying and measuring instruments to make straight roads, then built them all over the Empire.

They built strong, long-lasting bridges and buildings. They built sewers, not to prevent disease but to avoid the worst of the smells. And they built superb public lavatories – large open rooms with multiple seats but without partitions. They were clearly places where you went to chat, exchange gossip and jokes and generally pass the time of day. You can see splendid remains at Rome's port Ostia and at Ephesus in Turkey. At Housesteads on Hadrian's Wall the latrine was in the south-east corner of the fort. Rainwater collected in a cistern flushed the sewage out through a hole in the wall of the camp into the civilian settlement (vicus) outside, which gives some indication of the contempt they held for the natives.

Among the more endearing exhibits in the new display is a soldier's sewing kit – rather like one you might find in a hotel bedroom. The needles and three bobbins of thread in a wooden box would no doubt have been vital for the maintenance of the trooper's socks and shirts.

The Romans imported all sorts of other luxury goods to maintain their standard of living. A finger ring made from a single piece of amber has a relief carving of Minerva, who was goddess of wisdom and righteous warfare. This delicate piece of jewellery was made in the north-east corner of Italy and was probably worn to promote good dreams.

Writing materials were also symbols of luxury, especially when they were imported. Most legionaries were probably illiterate, so only the upper classes would have used them. Ordinary day-to-day writing was done with a bronze or bone stylus on a wax tablet. When the message had been read the wax could be smoothed over and used again. Various other writing materials have been found, including ink pots, pens, papyrus and pottery; a workman seems to have copied a quotation from Virgil's Aeneid on tiles, perhaps as part of a writing lesson.

Some of the most interesting finds have been wooden cards. At Vindolanda fort, near the east end of Hadrian's Wall, dozens of wooden postcards were unearthed, with masses of information, written in ink, about administrative details of the occupation and private lives of the upper class, including a birthday invitation from one woman to another.

At Carlisle is a rather grander card made from silver fir, which did not grow in Britain; so the card must have been imported. It is inscribed with the words s, which would have been part of the address, and shows that this was a recognised part of the Empire.

More like tourist tat is a fragment of blue glass from a commemorative charioteer cup. The daredevil charioteers were the football heroes of the time. People were massive fans and glasses were moulded with the images and names of the superstars to sell at the races. This particular glass was probably made in Rome.

Around AD200 the Romans carried out substantial repairs to the wall at Birdoswald and an inscription in stone refers to the Emperor Septimius Severus, who visited the area in order to try to resolve a dispute with the Caledonians. He brought his sons Caracalla and Geta with him. But the inscription does not mention Geta, because when Severus died in York, Caracalla won the ensuing power struggle, had the brother's name wiped off the stone and went back to be Emperor in Rome. There he is remembered in the Baths of Caracalla, for which he took the credit, even though they had been designed by his father. They could accommodate 1,600 bathers and the building was later used as a theatre (I saw Aida there in 1962) and to house the gymnastics in the 1960 summer Olympics.

Another of the colourful characters who visited Banna fort was the Emperor Marcus Aurelius Musaeus Valerius Carausius, whose name appears on milestone erected during his reign (AD286-293). He was commander of the British fleet in the Channel (Classis Britannica), and his main job was to chase pirates. He was supposed to return to Rome any money he captured, but he chose to keep it. When a crisis loomed he bought the loyalty of his sailors and an imperial title, then minted masses of coins with his face on them to fortify his position. He was not popular, however, and was murdered by his finance minister, Allectus.

This new gallery shows how the Romans brought with them to their northern frontier an entire way of life – military precision, building expertise, domestic luxuries and political corruption. And it's all on display at Tullie House.

The new Roman Frontier Gallery opens at Tullie House Museum, Carlisle, on 25 June www.tulliehouse.co.uk