The Helvetia thus brought under Roman sway was not all of the Switzerland of to-day. Some of the Swiss cantons were comprised in the old province of Rhætia, which was not subdued by the Roman arms until the days of the first Augustus. Then, however, the Rhætians, who were kindred with the Italian Etruscans, came so completely under Roman influence that to this day in the valleys of the Engadine a corrupted Latin tongue is spoken, somewhat similar to that of the Roumanians of the Balkan Peninsula. Under Augustus western Switzerland was incorporated with the Roman province of Gaul, having its capital at Lyons; eastern Switzerland was joined with Rhætia, having its capital at Augsburg. Thus early in history the difference between Gallic Switzerland and Teutonic Switzerland begins to show itself.
Helvetia was much favoured by the Romans and became in effect the frontier province for the defence of the empire against the Germans. After a time the Helvetians were but little distinguishable from the Romans, adopting their manners and their faith. Wealthy Romans loved to make their summer resorts along the lake of Geneva, and Aventicum, the Helvetian capital, became a great Roman city.
At Avenches (which was the Roman Aventicum) there are to-day but 2000 people, but there can be seen remains of a Roman wall four miles long and in some places 15 feet high. In the day of Vespasian the city was as big as Canterbury is to-day, and with its walls, theatre, and aqueduct could look down upon the miserable contemporary village of Londinium. Helvetia, under the Romans, followed, in fine, very much the same course as Britain under the Romans.
With the decay of the Roman power Helvetia, like Britain, was made to feel at the hands of the barbarians a harsh punishment for its acceptance of the Italian civilisation. In the third century of the Christian era the Alamanni swept over the country, looting and devastating and retiring. In the fourth century they came again and took possession of all the east. The Burgundians followed, and, to a greater degree than most of the civilised world, Switzerland had to face the horrors that followed the disruption of the Roman Empire. Gradually there emerged from the welter the beginnings of the Switzerland of to-day, in part representing the old Gallic Helvetians and Etruscan Rhætians, in part the Alamanni (Germans) and the Burgundians. With the coming of the northern invaders Christianity, which had supplanted Paganism in Helvetia as it had in Rome, was almost stamped out. But as the power of the Burgundians grew over that of the Alamanni the country began to turn again towards Christianity.
In the sixth century missionaries from Ireland did much to spread the Christian faith in Switzerland. The most famous of these was St. Columban, who established a monastery at Luxeuil, of which he soon made a storm centre, involving himself in constant troubles with the Gallic clergy and with the Italian Pope. There is extant a famous letter of his to Pope Boniface IV. It is addressed by him to "the most beautiful head of all the churches of entire Europe. The most sweet Pope, the most high President, the most reverent investigator." After that flood of "blarney" St. Columban goes on to complain of the infamia in which the Papal Seat is steeped. Out of that remonstrance nothing seems to have come, but when St. Columban joined issue with the masterful Queen Brunhilde of Burgundy he met a spirit as imperious as his own. To guard her own power in the Court of Burgundy the famous Brunhilde encouraged her grandson, the reigning king, to keep mistresses rather than to marry a queen. St. Columban referred to the children of these mistresses as a "brothel brood." Shortly after he was exiled by force from Luxeuil, and is next heard of at Nantes, ready, it seemed, to embark for Ireland, his native land. But he changed his mind, turned back on his tracks, and established himself on the lake of Constance, where he preached successfully to the heathen and threw their idols into the lake. Next St. Columban went over to Northern Italy, abusing his disciple St. Gall who was too sick to accompany him. St. Gall remained in Switzerland and founded the famous monastery of St. Gall, visited by Charlemagne in 883.
Charlemagne was particularly fond of Switzerland and the Swiss, and founded many monasteries and schools in the country. Often he resided in Switzerland, and it is from Switzerland that comes the story which tells that his justice and mercy were so well renowned as to be known even to the animals. There was, the story runs, near his palace at Zurich a chapel on the river-side where he had placed a bell for people to ring if they wished to appeal for justice. One day as he was at dinner this bell began to ring. None could inform him what was the matter. The bell rang a second time, and then a third. On this the emperor rose from the table, saying, "I am sure there is some poor man you do not wish me to see." He walked down the hill to the chapel, where, hanging to the bell rope, he found a snake. The snake led Charlemagne to a tuft of nettles, and examining the spot he found a large toad sitting on the eggs in the serpent's nest. At once, grasping the meaning of the appeal, Charlemagne passed sentence that the toad should be killed. The next day the snake entered the dining-hall of the emperor, climbed on the table, and, beckoning the emperor to remove the lid of his golden goblet, dropped into it a beautiful jewel.
With the death of Charlemagne his empire was broken up and Switzerland was doomed to centuries of struggle in the vindication of her independence. The story of that struggle is one of the most fascinating of the national records of the Middle Ages.