According to its late medieval founding legend, the trunk of a fig tree (ficus) carrying the Precious Blood of Christ collected by Joseph of Arimathea was washed ashore on the riverbank at Fécamp in the 1st century.

Immediately, a fountain of holy blood gushed from the site; the relic attracted many medieval pilgrims, enhancing the reputation of the city.

Fécamp, however, is mentioned in 875 as Fiscannum and in 990 as Fiscannus and as late as 1496[4] which stem from the Germanic root fisc (English "fish") with an unknown suffix.

The prehistoric site, on the high ground inland from the port of Fécamp, reveals human occupation dating back to Neolithic times.

The archaeological diggings around the Ducal palace (in the grounds of the present abbey) in 1973-1984 revealed some evidence of the La Tène Celtic culture and Gallo-Roman works.

For Fécamp, the French Wars of Religion ended in July 1593, when Captain de Bois-Rosé rallied the city to Henry IV of France after his conversion to Catholicism.

First practiced by three-masted sailing ships, Atlantic fishing trips could last more than six months, the time taken to fill the hold with cod, which were salted to preserve them.