Fait mathématique: 1347 is the concatenation of the first 4 Lucas numbers.
Culture générale: 1347 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Date historique: September 8th is the day in 1727 that a barn fire during a puppet show in the village of Burwell in Cambridgeshire, England kills 78 people, many of whom are children.