Cathedral over the ages

As the mighty Notre-Dame cathedral prepares to reopen its doors in a month's time after a devastating fire in 2019, a look back at five key dates in the Paris landmark's colourful history:

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Building the world-famous cathedral in the heart of the French capital began in 1160 and was not completed until almost a century later.

The project was spearheaded by the ambitious bishop of Paris Maurice de Sully and had several striking features, including vaults that reached up to 32 metres, according to a study published in the journal PLOS ONE in 2023.

But some elements of the Gothic building's construction remain unknown centuries later.