[2] This earlier church which stood on the site of today's cathedral, the Salvator Basilica of the Frankfurt Königspfalz (Royal Palace), was originally founded on September 1, 852 by the East Franconian King Louis the German and consecrated by the Archbishop of Mainz Rabanus Maurus.

The palace itself (of which the foundations can be seen next to the cathedral as an excavation site) was created at the beginning of the 9th century under Louis the Pious, the son of Charlemagne, and replaced a royal court of the Merovingians of the 7th century, who in turn had conquered the area around Frankfurt am Main from the Alemanni.

From the 11th century onwards, the royal Pfalz lost its importance as an itinerary residence of the German kings.

It was only in the Hohenstaufen period, around the middle of the 12th century, under Conrad III, that the pfalz was again used for Hoftage (gatherings of the mighty of the Empire).

[3][4] The imperial elections were held in the Wahlkapelle, a chapel on the south side of the choir (Hochchor) built for this purpose in 1425 (see the plan below) and the anointing and crowning of the emperors-elect as King of the Romans took place before the central altar–believed to enshrine part of the head of St. Bartholomew – in the crossing of the church, at the entrance to the choir (See the Plan to the right).

The most significant losses occurred in an attack by the Royal Air Force on 22 March 1944, when more than a thousand buildings of the old town, most of them half-timbered houses, were destroyed.