It was once the western tower of the church of St Eloi, from which it is now separated by a street.
St Eloi, erected about 1560 in the Gothic style, was deprived of its first two bays in the 18th century; the present façade dates from 1889.
Dunkirk is said to have originated in a chapel founded by St Eloi in the 7th century, round which a small village speedily sprang up. In the 10th century it was fortified by Baldwin III., count of Flanders; together with that province it passed successively to Burgundy, Austria and Spain.
He restored to the royal domain the lands that had been usurped by the great nobles and by the church; he maintained at Paris a luxurious, though, from the example he himself set, a disorderly court; he was a patron of the arts, and delighted in the exquisite craftsmanship of his treasurer, the goldsmith St Eloi.
Dagobert protected the church and placed illustrious prelates at the head of the bishoprics - Eloi (Eligius) at Noyon, Ouen (Audoenus) at Rouen, and Didier (Desiderius) at Cahors.