After its foundation by Charlemagne in the ninth century on a site of long-established religious significance (recent excavations below the church suggest the existence of a Roman cemetery), the church was constructed in its present form between 1100 and 1230.
After a disastrous fire in 1763, the spires and upper sections of the towers were demolished, and reconstruction shortly after produced the Gothic belfries, watchrooms and octagonal cupolae which survive today.
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