The Gallic wall of this city, was uncovered during archeological excavations in 1970.Both the gate site, and the historical run of the street, can be partly retraced.The minster served as a bishop’s see until 1529 during the Reformation.Today's congregation forms part of the Evangelical-Reformed Church of the Canton Basel-Stadt.
According to the archeologist Hans Rudolf Sennhauser this transfer presumably took place at the beginning of the 7th century under bishop Ragnacharius, a former monk of monastery Luxeuil.The western facade was finished sometime in the latter part of the 13th century.A third storey was added to Georgsturm, and the Martinsturm' Even though supported by massive pillars, an earthquake in 1356 destroyed five towers, the choir and various vaults.There is no historical evidence for the existence of a cathedral before the 9th century.
Built on the old foundations of the Haito Minster some time after the turn of the first millennium a new building in the early Romanesque style of the Ottonian period was built by order of Bishop Adalberto II (approx. Sometimes called “Adalberto Cathedral”, the three-nave cathedral is actually named after its patron Emperor Henry II, in German “Heinrich”.
In the 19th century two major restorations took place.