Making a miracle happen

Nice booklet based on annual lecture commemorating the lifting of the siege of Leiden in 1574. The lecture is always connected to the siege, and in this case on the logistical side. De Heijer shows that the flooding of the Holland countryside and the relief expedition were a pretty desperate gamble and required frantic improvisation.

Henk den Heijer, Holland onder water. De logistiek achter het ontzet van Leiden (Leiden 2010).

There had been some experience with inundation of the low lying parts of Holland in defence against the Spanish attacks, such as at Alkmaar the previous year. However, there was no guarantee that the water would rise high enough to make an impact on the besieging Spanish troops. It was also highly uncertain that the Dutch rebels would be able to break through to the city. And from a logistical perspective, everything had to be started from scratch in a few weeks. Finally, unexpected events caused delays and necessitated further efforts to supply the troops. A Spanish attack on Dordrecht diverted resources.

Den Heijer shows the complex and extensive character of the preparations. Numerous dikes had to be breached, for which hundreds of pioneers had to be recruited from the surrounding towns and countryside. In one case it was necessary to occupy a Spanish held dike before the pioneers could get to work. Also, the countryside needed to be evacuated.

At the same time the fleet was collected. This probably amounted to about 70 warships and 250 supporting vessels. Because of the low water levels in the flooded area, these could only be flat bottomed ships and many were improvised from grain and peat transports. There were also probably up to another hundreds transports needed to supply the fleet over the course of the campaign.

The ships were fitted with a motley collection of guns, mostly light and flexible. A few heavier pieces were included but these were highly impractical and ineffective. The whole expedition consisted of about 3000 soldiers, 3000 men to man the ships and 1000 pioneers. In contemporary terms, this was a major effort.

Given the unpredictable result of the flooding, the improvised nature of the operation and the setbacks it suffered, Den Heijer argues the relief of Leiden was indeed a miracle.