Prior to the current gothic cathedral, there was another church standing on the current site.

The oldest surviving part of the building is a chamber in the crypt at the centre of the apse, which takes its name from the Merovingian bishop, St Lubin (544–556).

It stands at a lower level than the rest of the crypt and is usually assigned to a rebuilding made after 858, when Chartres was burnt by the Danes.

It is manifestly some sort of confessio, and van der Meulen has argued that it was part of a complete east end, with ambulatory and chapels, parts of which he thought also survive.

This would make Chartres Cathedral the earliest known example of this type of plan in France. The theory contradicts the chroniclers who asserted that the church was completely destroyed by fire in 1020 and entirely rebuilt by Bishop Fulbert (reg 1006–28). The significance of the confessio is its identification of the earliest cult at Chartres with a local saint rather than the Virgin.

A piece of Oriental silk purporting to be the Virgin’s robe was presented to Chartres c. 876 by Emperor Charles the Bald. There is no firm evidence for the cult statue before the 11th century, and whether the Virgin played a major part in the religious life of Chartres before the 12th century may be doubted.

The CULT OF CARTS of 1145 and the building operations connected with it were partly in honour of the Virgin, but the transformation of the cathedral into a recognizable pilgrimage church was accomplished only in the rebuilding after 1194, when the transepts were introduced. Even then the role of the Virgin in the total imagery of the cathedral was subordinate to a grander vision of the Church and the Christian picture of world history.

Evidence for the cult is meagre and perplexing. By definition it ought to have been a major attraction; yet it seems to have been taken seriously only by the well-to-do, and there are few miracles associated with it. The cult may have been a promotion that gathered momentum slowly as Chartres subsided into the status of a provincial cathedral city, and the clergy sought consolation for the lost greatness of the past.

The great days of Chartres were those of the 11th-century cathedral school, when Fulbert and his pupils taught there. By 1140 its reputation was already fading. It is not entirely fanciful to detect a causal relationship between the decline of the school and the development of the cathedral as a showpiece of religious art.

In later times much trouble was taken to keep alive Fulbert’s connection with the building and to obscure the fact that most of it was not his. He was certainly responsible for nearly all the crypt, and this determined the widths and bay lengths of the Gothic cathedral.

An illustration of Fulbert’s church in a contemporary manuscript (Chartres, Bib. Mun., MS. n. a. 4) shows a basilican church with radiating chapels at one end and a single tower or tower porch at the other. There were no transepts. It was quite unlike its successor, but the main arcade of the Gothic building may correspond to that of its predecessor, and the level of the 13th-century vault springers may coincide with the 11th-century roof-line.