The watermills and the possessions of the chapter of Onze-Lieve-Vrouw along the Jeker

In the Middle Ages dozens of people were attached to the chapter of Onze-Lieve-Vrouw, including twenty canons (members of the chapter). All of them lived on the income from the chapter's possessions in and around Maastricht. The charters show where these were located, and it is striking how many of them lay along the river Jeker. Some were in the town itself, such as a house (no. 52) opposite the Hilarius Chapel (now the Walloon Church). But most lay somewhere between Maastricht and Tongeren, such as farmsteads at Glons (Glaaien, no. 10) and Kanne (nos. 5 and 6) and farmland in Wonck, Emael and Kanne (nos. 7 and 11). The chapter was entitled to levy a tax on the yield of that land, the tithe. This levy was paid in kind: the chapter received a share of the grain.

The chapter's acquisition of its first two watermills

Linked to the farmland was another economic activity of the chapter: the operation of watermills. The very first charter of the chapter of Onze-Lieve-Vrouw dates from August – 23 September 1096 (no. 1). It concerns two watermills on the Jeker that were transferred to the chapter of Onze-Lieve-Vrouw by Bishop Otbert of Liège. The year and month of this charter are no coincidence. On 10 August 1096 Godfrey of Bouillon set out for the Holy Land on the First Crusade, together with many nobles from the Maastricht area. To equip his army, Godfrey sold his possessions to the Bishop of Liège, on condition that he could buy them back at the same price on his return. In the summer of 1096 Bishop Otbert needed a great deal of money to buy and maintain the crusaders' possessions. For that reason he sold the two watermills on the Jeker to the chapter of Onze-Lieve-Vrouw, which thus in effect helped to pay for the crusade. Otbert was lucky, incidentally: Godfrey of Bouillon died childless in the Holy Land four years later, so the bishop was allowed to keep Godfrey's possessions. But in 1096 the bishop could not have foreseen that.

The link between the acquisition of the mills and the founding of the Norbertine convent of Sint-Gerlach

According to the charter, the fifty silver marks the chapter needed to buy the two mills came from an estate near Houthem. That estate was sold to Lord Goswin I of Heinsberg, Lord of Valkenburg. In 1202 his successor Goswin IV would donate the same estate to the Norbertine order to found a monastery at the grave of the holy hermit Gerlach, who had died in 1165. That donation of 1202 was also connected with a crusade. With it, Goswin IV bought off the papal excommunication that had been imposed on him for breaking his crusader's vow to take part in the Fourth Crusade.

The first watermills

The technology of the watermill had been brought to Europe from the Middle East by the Romans. The first known European watermill stood on the river Tiber in Rome in the year 20 BC. But watermills were soon built north of the Alps as well, as shown by a mill found in 2009 on the river Inde in Düren, near Aachen. This is the oldest known watermill north of the Alps. Finds at this grain mill indicate that it dates from as early as the first century AD, in other words from shortly after the arrival of the Romans. At that time spelt was the most popular grain in the Maastricht area. After the harvest it was hulled to separate the chaff from the grain. This hulling was done between two millstones, the bedstone and the runner stone.

The mills of the chapter of Onze-Lieve-Vrouw

Spelt was also widespread in the Middle Ages. However, the technology of the watermill had been lost after the collapse of the Roman Empire, so millstones were usually driven by people or animals. That is what makes the watermills of Maastricht so special. In the twelfth century watermills were a feat of technical ingenuity. Only in the eleventh and twelfth centuries were they once again built on a large scale. They were the most important reinvention in Europe until the arrival of the steam engine. The watermills were made entirely of wood (sluices, wheel and internal parts). Building a mill also required mastery of the techniques needed to construct the dykes, sluices and channels that drove the mill wheel. These mills were in great demand. Agriculture had switched from spelt to wheat and was moving on from wheat to rye. To bake bread from rye, the rye first had to be ground, and that required a mill.

This first charter of the chapter of Onze-Lieve-Vrouw concerns grain mills that could grind rye and spelt. The two mills were located within the town walls. They may have been the Bisschopsmolen and another mill that must have stood close by. The Bisschopsmolen is the oldest working watermill in the Netherlands. Spelt is still ground there today!

Legal and economic context

To understand the significance of the watermills for the chapter, more information about the legal and economic context is needed. The supply of grain was guaranteed by mill soke: people were obliged to have all their grain ground at the chapter's mills. Because part of the grain had to be paid as a milling fee, the chapter gained a substantial income. In addition, the chapter needed the right to build and operate a mill, as well as a damming right to raise the water of the Jeker to a certain level so that there was enough fall for the water wheel.

It is hardly surprising that the chapter of Onze-Lieve-Vrouw was willing to buy the bishop's watermills. That it did not stop at these two mills in the town is clear from the third charter of the chapter of Onze-Lieve-Vrouw (no. 3). This records that in 1133 an undeveloped plot of land along the Jeker was acquired from Bishop Alexander I of Liège, with the right to build two more mills there. This land lay at Viertoren, in the Jeker valley. What is special about this charter is that the chapter shared the risk of building and operating the mill with the presumed miller. In this charter it was agreed with a certain Bertold that he would compensate the canons of the chapter if the new mills proved unprofitable. A charter from 1158 shows, incidentally, that the mills at Viertoren were indeed built (no. 5). The construction of these two additional mills was presumably also an economic success for the chapter. The economic importance of watermills to the chapter is further shown by charters from 1158 and 1186 that mention a mill further upstream on the Jeker at Glons (nos. 5 and 7).

Conclusion

In the thirteenth century the chapter of Onze-Lieve-Vrouw drew income from at least five watermills along the Jeker. Owning these watermills secured the chapter a steady income (in grain). Their importance can be inferred from the fact that the charter of 1096 was signed in the chapter house in Maastricht and contains the names of the provost and the dean of the chapter.