Short answers, pulled from the story.
Construction of Notre-Dame de Paris began between the 24th of March and the 25th of April 1163, with the laying of the cornerstone in the presence of King Louis VII and Pope Alexander III. The cathedral was largely completed by 1260, though it was modified in succeeding centuries.
The fire at Notre-Dame broke out on the 15th of April 2019 at 18:18 in the cathedral attic. It was speculated to be linked to ongoing renovation work. The flèche collapsed at 19:50, bringing down 750 tonnes of stone and lead, and about 500 firefighters helped battle the blaze.
Notre-Dame de Paris reopened on the 7th of December 2024 in a ceremony attended by 1,500 world leaders and dignitaries. The restoration cost an estimated $739 million and took more than 2,000 days to complete.
Eugène Viollet-le-Duc was the architect appointed in 1844 to lead the 19th-century restoration of Notre-Dame, alongside Jean-Baptiste Lassus. He supervised the restoration from 1844 to 1864, at a total cost exceeding 12 million francs, and added the ornate 750-tonne spire that would collapse in the 2019 fire.
Notre-Dame holds some of the most significant Christian relics in Europe, including the crown of thorns, a nail from the True Cross, and a sliver of the True Cross, originally purchased by King Louis IX from the Latin Emperor Baldwin II. The crown of thorns was returned to the cathedral on the 13th of December 2024.
Notre-Dame suffered extensive damage during the French Revolution. In 1790, bronze, lead, and precious metals were stripped out. By 1793 the cathedral had been rededicated to the Cult of Reason. Napoleon restored it to the Catholic Church through the Concordat of 1801, finalised on the 18th of April 1802.