4.1 Date of cargo and shipwreck
Apart from the later intrusions, the assemblage should be regarded as a closed find, contemporaneous to the day that the ship went down. Despite the dynamic environment which caused the remains to be found uncovered or encapsulated in loosely shifting sands, there is strong unity and a strong correlation between the finds in the articulated wreck mound and those that were found in excavation. There is very little in the way of contamination and later intrusions. Parts of the cargo include dating clues, and other parts are dated accordingly.
The stamps on the lead from the Olkusz region include numbers, but cannot be linked to a date. The lavish presence of the marks of hooks or lifting thongs could indicate prolonged circulation, including repeated handling and warehousing as opposed to rapid delivery, but there is no benchmark for the number of actions involved in handling and transportation. For the iron bars and their industrial production, the date of other materials must be conclusive. Indications are more direct regarding the tin from the Erzgebirge. Many of the stamps have dates. They range from 1556 to 1630 and are related to the establishment of the mining venture and of quality patents under the patronage of the Habsburg Bohemian kings and Holy Roman emperors Ferdinand I and Rudolf II. The tin rolls were repacked in barrels at an intermediate stage and an extended period of warehousing and circulation before packing and use cannot be ruled out. Their final shipping was not before 1630, however.
The leather is dated by means of the other categories. It is unlikely to have been in circulation very long. Dated in the same way are its production according to various cultural traditions in dispersed small-scale tanneries and its lumping in bales of uniform composition of nevertheless varying quality – processes that were probably directed by a middleman. This also applies to the shipment of mercury in square bottles, to the brass wire pins with twisted heads, the ivory, pepper, shot and miscellaneous cargo. The armament and inventory are poorly conclusive, although the cast-iron cannon are assumed to be typical of the 1630s. The only two categories that add to the dating are the ship itself and the textiles as attested by the lead cloth seals.
A sample of the keel has a total of 148 rings, with no sapwood rings present. Dendrochronologically, the rings are dated to the years AD 1465 to 1612, with the best fit on the Westphalia curve (GL=67.3; t= 7.43; p= >99. 9%; Jansma & Spoor 1991). The tree was certainly felled after AD 1612. The absence of sapwood does imply, however, that an unknown number of missing rings must be added. In response to a tendency to make low estimates, Jansma (1995) developed rules of thumb for correction, and in applying these Jansma & Spoor (1991) posit that the tree was felled after AD 1632 ± 6. The correction rules are not written in stone, however, and although a felling date late in the first half of the 17th century would be consistent with the analysis, a felling date in the 1620s is equally plausible. Dendrochronology, dendrochronological provenancing and its application in ship research have continued to develop over the last 20 years (Daly 2007; Nayling 2008), and it is regrettable that only one sample was taken.
The lead cloth seals are deemed highly relevant to dating the wreck. For one thing, the only and recurring date is the Leiden production date of 1635 (fig. 43). For another, the detailed studies of the industries in Hondschoote (Coornaert 1930) and Leiden (Posthumus 1939) show that both centres increased capacity during this period to meet immediate demand. It is improbable that the expensive high-quality sayes were stored in the production centres for any substantial period of time.
In conclusion, we assume that the ship was built in the 1620s or early 1630s. It was laden in 1635 at the earliest, or quite shortly afterwards. A date for the wreck between 1635 and 1640 is the most plausible.