The number 17 and particularly the date of 17th January appears to have a special significance in relation to Rennes-le-Château:

• 17^th January 681 was the date Sigisbert IV was reputed to have arrived at Rennes-le-Château. He is the mysterious link in the Merovingian line who, as son of Dagobert II, would have been his heir and pretender to the throne of France
• 17^th January 872 the lost body of Dagobert II was supposedly rediscovered
• 17^th January 1329, Ste. Roseline died in Arcs, Provence
• 17^th January 1601, Ste. Germaine died in Pibrac near Toulouse (at the age of 22)
• 17^th January 1893 Monseigneur Billard, purchased Notre Dame de Marceille in Limoux
• 17^th January 1967 Publishing date of Le Serpent Rouge
• 17^th January Feast day of St. Sulpice
• 17^th January Feast day of St. Anthony (he died 17^th January 461, allegedly at the age of 105)
• 17th of January 1862, the Bishop presiding over the apparitions of Bernadette at Lourdes announced that the sightings were of divine origin
• 17^th January a ray of light in the church of Rennes-le-Château passes through the stained glass window upon St. Anthony
• 17^th January 1381 Nicolas Flamel allegedly produces silver out of mercury
• 17^th January 1377, Pope Gregory XI reached Rome after leaving Avignon on 13 September 1376, ending the Babylonian Captivity
• 17^th January 1781 Marie de Negre D’Ables died at the age of 67
• the number 17 is displayed on the tombstone of Abbé Jean Vié of Rennes-les-Bains, the predecessor of Henri Boudet. Although he died on 31st August 1872, the stone displays: Mort le 1er 7bre 1872. Summarizing: 17 Jean Vié, 17 Janvier, 17^th January
• 17^th January 1917 Marie Dénarnaud discovered Saunière prostrate on the Belvedere after a stroke
• 17^th January 1975 Archduke Rodolphe of Habsbourg visited Rennes-le-Château
• One of the fundamental documents of the French Revolution, the Declaration of the Rights of Men and of the Citizen counts 17 articles
• the Sanctuary of Notre-Dame de Marceille was sold to 17th January 1893