According to some old traditions, the Cathedral is built on a spot, which, from the remotest times, had been devoted to worship. Originally this spot formed a hill sloping westward into a cavity, which was filled up many centuries ago. Around it, the Celts, the first inhabitants of our country, built their huts: its summit was covered by the sacred wood, in the midst of which rose the druidical dolmen. It was there that those barbarians offered sacrifices to Esus, their God of war, sacrifices which, in times of public calamity, were human victims.

After the conquest of Gaul by the Romans, a regular and fortified town was very soon founded on the place hitherto occupied by the scattered habitations of the Celts. The old name of Argentorat was alone preserved; it signified a town where the river is crossed over. It was there, according to tradition, that a temple dedicated to Hercules and Mars succeeded the druidical forest. There is nothing unlikely in these traditions; the high ground on which the Cathedral stands speaks as much in their favour as the pagan statues found in the neighbourhood[1].

[1] A brass statue of Hercules, called Krutzmann, was found among the christian statues that decorated the Cathedral; it was taken down in 1525 and is no longer extant. A Hercules of stone, found no doubt when digging the foundations, is yet seen in a niche of the northward tower, where it juts out into the nave. A small stone figure of Mars, coming also from the Cathedral, was preserved in the town-library, but it appeared to be modern.

With respect to the first erection of a christian church in this place, history is destitute of authentic facts. Some old chronicles report that about the middle of the fourth century, saint Amand built a church on the ruins of a Roman temple, but the existence of this supposed first bishop of Strasburg is even very doubtful. During the first years of the fifth century, the invasion of barbarians filled the provinces of Gaul with terror and devastation; the German tribes that crossed the Rhine plundered the Roman city of Argentorat and its temples. Nobody knows whether from that time new inhabitants settled in the midst of these ruins, or whether they served but as temporary abodes to the hordes successively coming into Gaul.

It was only after the conquest of that extensive country by the Franks that, about 510, Clovis had a church built at Argentorat, no doubt on the spot where the Cathedral now stands. The architecture of that church was as coarse and barbarous as the spirit of those times; it was built of wood and supported by earthen walls, extending from East to West; on this latter end was the front-gate and before it a portico; besides the principal nave it had two aisles; the western side opening into a yard that served as a passage to the priest's house.

In proportion as the town, the name of which was by the Franks changed into Strasburg, increased in importance and population, the Merovegian kings granted greater favours to the church founded by one of their predecessors. The valuable donations they bestowed on the bishopric of Strasburg, enabled the inhabitants to embellish and enlarge the Cathedral. In 675 Dagobert II granted to bishop Arbogast the town of Ruffach with the castle of Isenburg and a vaste domain that he freed from tax and royal jurisdiction and which on that account was called superior Mundat. A no less important gift was that from Count Rudhart, who made over to the church of Strasburg, in 748, Ettenheim with several neighbouring villages on the right bank of the Rhine. Many other eminent personages of this country increased successively by their liberality the wealth of the episcopal see. A great advantage was granted by Charlemain in 775, which was to exempt the subjects of the bishopric from all tolls and taxes imposed upon the traders travelling through the empire. At that time considerable sums had already been employed to adorn the interior of the Cathedral. In the year 826, the abbot Ermold the Black, living in exile at Strasburg, speaks with enthusiasm of the beautiful temple of the Virgin and of the other altars that decorate it. This ecclesiastic, with great ardour changed the metal of the antique statues he could yet find into sacred vases; a bronze Hercules, two cubits high, alone escaped the pursuit of his pious zeal; after preserving it several centuries in the Cathedral, it was at last sold, and is now at Issy near Paris.

A fire, which in 873 destroyed a portion of the church and all its archives, occasioned, no doubt, important repairs, and this event was the cause of a new royal confirmation of all the possessions of the church. In 1002 it was plundered, profaned and set on fire by the soldiers of Hermann, duke of Suabia and Alsacia, who was then contending with Henry of Bavaria for the imperial crown, Strasburg and its bishop Wernher having declared for the latter. Subdued by Henry II, Hermann was compelled to repair the damage caused to the church by placing at bishop Wernher's disposal the income of the abbey of Saint-Stephen of which he was the patron. With these funds, which the bishop increased by means of a new levy of taxes and by indulgences, he was preparing to restore his Cathedral, when in 1007 a thunderbolt achieved its destruction.

He then formed the project of rebuilding the church on a plan of much larger dimensions and after the style of architecture that was then making its first appearance. The revenues of the bishopric, contributions furnished by the clergy of Alsacia and large sums of money granted by the head of the empire, afforded Wernher the necessary resources for the execution of his plan. This was examined and discussed in the presence of several master-architects whom he had sent for. The plan once fixed upon, stones were brought from the fine quarries of free-stone in the Kronthal. The peasants and bondsmen of the country brought them to the town where they were cut in the square then called Frohnhof, between the Cathedral and the present palace. It was during these labours that in 1042 the emperor Henry II came to Strasburg; the dignified and austere deportment of the clergy of the high chapter, the tranquillity prevailing under the roof of the episcopal church, made such an impression on this prince, that he for a moment resolved to resign the crown and solicit his admittance among the canons of the Cathedral. The bishop appeared at first to accede to this wish; but it was only to prescribe to Henry, henceforth his subordinate, to resume the imperial authority which Providence had bestowed on him; the emperor acquiesced and perpetuated the remembrance of his pious wish by the foundation of a royal prebend.

When, in 1015, a sufficient quantity of materials was collected, they set to work by digging the ground. At the depth of more than five fathoms they drove down stakes, filled the space between them with clay mixed with lime, fragments of bricks and coal; and on this solid base were laid the foundation stones.

Tradition gives an account of a hundred and even two hundred thousand men being employed in the construction of this church, which work, thanks to the religious enthusiasm of that epoch and the labours performed by vassals and workmen for the salvation of their souls, advanced very rapidly.