On 1 Aug 1765 the Mozart family sailed across the English Channel from Dover to Calais, leaving England after a stay of fifteen months. Leopold Mozart now planned to take the family to The Hague, because Princess Carolina, the sister of William V, Prince of Orange and stadtholder of the Dutch Republic, had made a special request to hear the Mozart children (see our entry for 18 Sep 1765).

The interval between the family’s arrival in Calais and their arrival in The Hague on 10 or 11 Sep is poorly documented. Leopold Mozart sent no letters at all to Lorenz Hagenauer between 9 Jul and 19 Sep 1765, and his letter on 19 Sep, which summarizes their activities in the interim, provides no precise dates between 1 Aug and the date of the letter. Mozart scholars have long attempted to reconstruct the chronology of this portion of their journey using clues in Leopold’s letter and his travel notes. We know that the family proceeded from Calais to Dunkirk, then via Bergues to Lille, where, Leopold writes, they remained for “four weeks” because Wolfgang had a bad cold and Leopold suffered a period of serious dizzy spells and vomiting. From Lille they traveled to Ghent, where they remained just one day, then Antwerp (staying over a Sunday, which must have been 8 Sep), then via Rotterdam to The Hague, where we can be reasonably certain they arrived on 10 or 11 Sep. Traditionally, Mozart scholars had assumed that the family stayed only briefly in Calais and Dunkirk. Deutsch, for example, has the Mozarts traveling to Dunkirk on 3 Aug and from there to Lille on 5 Aug (Dokumente, 47–48; for a more detailed discussion, see Eisen 2015). The commentary to Briefe (v:140) has them staying only overnight in both Calais and Dunkirk.

Two documents have recently come to light showing that these earlier guesses about the family’s stays in Calais and Dunkirk were incorrect. The first is an entry in the manuscript diary of Emmanuel de Croÿ-Solre, Duc de Croÿ, who records that the Mozart children performed at a party he gave in Calais on 4 Aug 1765 (see our entry for that date and Eisen 2015). The other new document is shown above: an inscription on the back of an exemplar (now in the collection of Christopher J. Salmon) of the Delafosse engraving of Carmontelle’s watercolor portrait of the Mozarts. The inscription is difficult to decipher, but reads “ils Etoient a Dunkerque les 9 & 10 aout 1765” (“They were in Dunkirk on 9 and 10 August 1765”).

The inscription is written in iron-gall ink, probably with quill pen, and the spelling (“Etoient”) and handwriting are consistent with the time referred to. There is, in any case, no reason to think that the inscription dates from substantially later than the time of the Mozarts’ visit. It seems likely to have been added by the first owner of the print, who may have received it from Leopold himself when the Mozarts were in Dunkirk.

The inscription places the Mozarts in Dunkirk several days later than had traditionally been thought (3 or 4 Aug), and later even than the revised chronology suggested by Eisen, who places them in Dunkirk on 5 Aug “or just after” (Eisen 2015, 167). Dunkirk is a bit over 40 km from Calais by road, a trip that in the eighteenth century could easily have been made in the space of a single day. If the dates given in the inscription on the print are correct, and the Mozarts were in Dunkirk on 9 and 10 Aug 1765, then they may have stayed in Calais until as late as 8 Aug. If so, they spent an entire week there rather than simply stopping overnight.

The identity of the original owner of the inscribed exemplar of Delafosse’s engraving is unknown, but it is reasonable to begin by investigating the names in Leopold’s travel notes for Dunkirk. He writes:

⁣                       Dunkirchen
                                                Logé
⁣                                     à St: Catharine

Mr: Pierre Lemaire Marchand
            Rue des Carmes.
Mr: Le Chevalier de Mezziers Commendant.
Mr Clabau Organiste et son fils et fille
Mr: Van der ber.
[Briefe, i:197; Schurig 1920, 39]

“Mr: Le Chevalier de Mezziers Commendant” was probably Eugène-Eléonor de Béthizy de Mézières (also “Béthisy”, 1709–1781), known as the Marquis de Mézières, who attained the rank of lieutenant general and was governor of Longwy, near what is now the junction of France, Belgium, and Luxembourg. Eugène-Eléonor was evidently interested in opera, and published two pamphlets: Critique d’un livre contre les spectacles intitulè J. J. Rousseau, Citoyen de Genève, à M. D’Alembert (Amsterdam, 1760), and Effets de l’air sur le corps humain, considérés dans le son; ou Discours sur la nature du Chant (Amsterdam, 1760, with a second edition in 1765). His interest in music probably explains, at least in part, his acquaintance with the Mozarts.

The previously unidentified “Mr Clabau” in Leopold’s travel notes was the organist Hyacinthe Clabault (c. 1701–1770), maîtrise (choir master) at the Église Saint-Eloi in Dunkirk (see Declerck 2002). Hyacinthe had numerous children; Declerck lists ten. Three of Hyacinthe’s children are known to have been musicians. Michel Adrien Clabault (1741–1820) was a violinist, “symphoniste,” and organist at the Église Saint-Eloi; born on 24 Dec, he would have been 23 at the time of the Mozarts’ visit. Marie Catherine Isabelle Clabault (1746–1804) was active as an organist and keyboard teacher in Dunkirk; born on 5 Jan, she would have been 19 at the time of the Mozarts’ visit. The birthdate of Henri Clabault seems to be unknown, but he married in 1759 (Declerck 2002); he was also an organist, and is said to have succeeded his father at the Église Saint-Eloi (see the record for his sister Marie Catherine Isabelle at Muséfrem). Following Clabault’s name, Leopold writes “son fils et fille” (both singular). We cannot be certain which children these were, but Marie Catherine Isabelle seems likely to have been one of the daughters, and the son seems likely to have been either Henri or Michel Adrien.

“Pierre Lemaire” in Leopold’s travel notes was probably Pierre Jacques Lemaire (c. 1722–1777), a violist and player of low strings who lived in Rue des Carmes (later renamed Rue de la Couronne) around this time (Declerck 2002; on the street name, see Derode 1852, 52). Why Leopold referred to him as “marchand” is unknown, but the identification is plausible because of Pierre’s musical interests and the matching street name. “Mr: Van der ber” has not yet been identified.

The exact location of “St: Catharine,” where the Mozarts lodged in Dunkirk, remains uncertain, but it seems to have been on or near the Rue du Sud, so named because it originally ran along the town’s southern rampart. Derode (1852, 63) names Sainte-Catherine as the fourth of six contiguous houses built along the Rue du Sud by Joseph Thierry upon acquiring the property in 1750. However, the diary of Henri Verbeke, a lawyer and magistrate in Dunkirk, records that the King of Prussia (Frederick the Great) lodged at the “l’Hôtel de Sainte-Catherine, sur le quai de Mardyck” during an incognito visit to Dunkirk on 10 May 1763 (Carlier 1914, 250–51). Both the Rue du Sud and the nearby Quai de Mardyck are shown on this 1764 map of Dunkirk, as are the Rue des Carmes and the Église Saint-Eloi.

Leopold writes to Hagenauer that he had particularly wanted to see the fortifications in Dunkirk, which were in the process of being demolished, in accordance with a provision of the Treaty of Paris (1763) ending the hostilities between France and England in the Seven Years’ War. Leopold writes:

In Calais war die Duchesse de Montmorency und der Prince de Croy unsere Bekanntschaft; und ich gieng von da nach Dünkirchen, welchen Platz ich wegen dem Port und wegen dem ewigen streitten zwischen Engelland und Franckreich in betreff der demolition der Vestungswerker sehen wollte. Der Platz ist sehr schön, die Gassen sind meistens gross und die meisten Häuser sauber. Eine hübsche Börse, starcke Handelschaft, und leyder, die schönsten Vestungswerker bereits niedergerissen. Ich sage: leyder! weil es schmerzet so schöne Werker, die so viel Geld gekostet demolieren zu sehen. Bey allem dem, waren die Engelländer noch nicht zu frieden, und man beschwerte sich in Engelland immer, daß man die Wercker nicht alle demoliert hätte, so wie es in den Friedens Puncten wäre ausgemacht worden. Es würde demnach eine Comission beliebt, wo der Duc de choiseul von Franckreich und der Duc de Bedfort in Dünkirchen zusammen kommen, und die sache untersuchen solten. [Briefe, i:201]

In Calais we became acquainted with the Duchesse de Montmorency and the Prince de Croÿ; and I went from there to Dunkirk, which I wanted to see on account of the port and on account of the eternal strife between England and France over the demolition of the fortifications. The place is very beautiful, the streets are mostly large and most houses are clean. A handsome exchange, strong trade, and sadly the most beautiful fortifications already dismantled. I say: sadly! because it is painful to see such beautiful structures, which cost so much money, demolished. With all that, the English were still not satisfied, and there were complaints in England that the workers had not demolished everything that had been agreed in the provisions of the peace treaty. So a commission was established in which the Duc de Choiseul from France and the Duke of Bedford met in Dunkirk to investigate the matter.

Dunkirk is positioned at the northernmost point of France, on the border of what is today Belgium, but was then the Austrian Netherlands. Dunkirk is also around 75 km across the English Channel from Dover, and thus occupied a position of chronic strategic worry for England. The English were awarded Dunkirk in 1658 at the end of the Eighty Years’ War, but sold the city to the French four years later. Sébastien Le Prestre de Vauban (1633–1707), Louis XIV’s great military engineer, subsequently oversaw the construction of elaborate fortifications around Dunkirk, making the town essentially impregnable to attack from the sea. A view of the town from 1713 shows a long channel crossing the broad and shallow tidal plain, flanked by two jetties protected by small forts, thus strictly controlling access of ships to the protected harbor within the fortifications. Because of the shallow tidal plain, the town itself was out of range of cannon fire from ships in the English Channel, and the forts were intended to protect the more vulnerable channel and jetties.

The well-protected harbor at Dunkirk soon became a staging ground for privateers preying on the commercial shipping traffic in the Channel.

According to Article IX of the Peace and Friendship Treaty of Utrecht between France and Great Britain (1713), ending hostilities between those two countries in the War of the Spanish Succession, France agreed to dismantle Vauban’s fortifications and fill in the harbor:

The most Christian King [Louis XIV] shall take care that all the fortifications of the city of Dunkirk be razed, that the harbour be filled up, and that the sluices or moles which serve to cleanse the harbour be levelled, and that at the said King's own expence, within the space of five months after the conditions of peace are concluded and signed; that is to say, the fortifications towards the sea, within the space of two months, and those towards the land, together with the said banks, within three months; on this express condition also, that the said fortifications, harbour, moles, or sluices, be never repaired again. All which shall not, however, be begun to be ruined, till after that everything is put into his Christian Majesty's hands, which is to be given him, instead thereof, of as an equivalent. [Wikisource, corrected]

Although demolition was indeed undertaken, there seems to have been foot-dragging and a somewhat creative interpretation of the treaty on the part of the French, and the issue of the Dunkirk fortifications became an open sore in British politics over the ensuing decades (see Moore 1950). The Treaty of Aix-la-Chapelle (1748) at the end of the War of the Austrian Succession kicked the can further down the road by stating merely that the French should abide by prior treaties regarding Dunkirk.

⁣                Article XVII.
⁣     Dunkirk shall remain fortified on
the Side of The Land, in the same Con-
dition as it is at present; and as
to the Side of the Sea, it shall remain
on the Footing of former Treaties.
[Definitive Treaty 1749, 27]

A map of Dunkirk from 1751, before the start of the Seven Years’ War, shows that there had indeed been a significant paring back of the town’s fortifications.

The jetties on the channel to the sea seem to have been modified, and the forts on the tidal plain are no longer shown, suggesting they had been demolished. But it was by no means the complete demolition envisaged in the treaties of 1713 and 1748. The 1751 map also shows a new canal coming from Mardyck, which ultimately also led out to the sea.

An English map from a few years later, “An accurate plan of Dunkirk with its fortifications as they were in 1757”—that is, around the beginning of the war—shows a “New Canal made in 1754” on the east side of the town, and three new forts on the tidal plain near the entrance to Vauban’s canal, two of which are marked as having been built in 1755.

The Duc de Croÿ, at whose party the Mozart children would perform in 1765, is said to have played a direct role in improving Dunkirk’s fortifications at the beginning of the Seven Years’ War:

Dunkerque possédait en ce temps un homme très-dévoué aux intérêts du Roi et de la ville. C’était le prince de Croy et de Solre-le-Château, seigneur des deux fiefs de Condé maréchal des camps et armées du Roi. Il s’entendait admirablement avec M. Le Beuf, brigadier d’infanterie, directeur des fortifications, et faisait marcher les travaux avec une célérité inouïe. En 1757, tout le côté occidental du port n’avait qu’un simple talus, et, déjà en 1758, le Prince avait fait construire, à partir du bassin, un quai qui, au mois d’août 1759, était poursuivi jusqu’à la chaîne du chenal. [Bertrand 1865, 220]

At that time Dunkirk had a man very devoted to the interests of the King and the city. He was the Prince de Croÿ et de Solre-le-Château, lord of the two fiefs of Condé, and field marshal of the King’s armies. He got along admirably with Mr. Lebeuf, brigadier of the infantry and director of fortifications, and he made the work progress with incredible rapidity. In 1757 the entire western side of the port had only a single rampart, and already by 1758 the prince had had a quay constructed, starting from the basin, which by August 1759 had been continued up to the chain in the channel.

The “chain” (which in this usage means a barrier to entry to a port) is undoubtedly the “boom” marked halfway up the channel to the sea on the English map from 1757, and was probably a checkpoint for incoming ships. It may be that Leopold’s interest in the fortifications at Dunkirk was inspired, at least in part, by meeting the Duc de Croÿ at the party in Calais on 4 Aug 1765.

In the event, the English did not attack Dunkirk or indeed any point on this well-defended portion of the French coast during the Seven Years’ War. Article XIII of the Treaty of Paris (1763) at the end of the war (the treaty that Leopold is referring to) likewise reaffirms prior treaties, but is now more explicit about the demolition to be undertaken at Dunkirk:

XIII. The town and port of Dunkirk shall be put into the state fixed by the last treaty of Aix la Chapelle, and by former treaties. The Cunette shall be destroyed immediately after the exchange of the ratifications of the present treaty, as well as the forts and batteries which defend the entrance on the side of the sea; and provision shall be made at the same time for the wholesomeness of the air, and for the health of the inhabitants, by some other means, to the satisfaction of the King of Great Britain. [Wikisource]

A map of Dunkirk dated 29 Dec 1762 shows the state of the fortifications at the end of the war. The “Cunette” is the channel to the east of the town (to the left on this map), between it and the outer ring of fortifications. The map indicates that the small forts on the tidal plain are to be demolished, and the map’s legend specifies other recently added or renovated defensive fixtures that were also to be destroyed.

The map of Dunkirk from 1764, the year before the Mozarts’ visit, suggests that much of the outer ring of fortifications around the town had already been demolished, as Leopold’s letter suggests.

With these newly documented dates for the Mozarts’ stay in Dunkirk, we can offer a revised itinerary for the period between their arrival in Calais and their arrival in the Hague. (Documented dates are in green, reasonably certain dates in blue, and speculative dates in red.)

It now seems likely that the Mozarts remained in Calais for a week (1–8 Aug 1765), and spent two days in Dunkirk (9–10 Aug 1765). One wonders whether they might have given a concert in Dunkirk. Their contact with Clabault suggests that Wolfgang may have had the opportunity to play the organ in the Église Saint-Eloi, something that Leopold made a special point of arranging for his son to do at many stops on their tour.