The Hollandic Water Line (Hollandse Waterlinie)

William of Orange ordered the start of modernization work on the medieval fortifications around Loevestein in 1575. By the end of 1589, ramparts in the form of a pentagon, three bastions, a half bastion and a roundel were in place. The medieval roundel was replaced with a new bastion in 1651. The stronghold has hardly changed in form since this time.

During the Dutch Revolt, or Eighty Years’ War (1568–1648), Loevestein served as one of several strongholds along Holland’s eastern border.

In 1672 – the year in Dutch history referred to as the year of disaster (Dutch: rampjaar) – French troops under Louis XIV invaded the country. This prompted an ad hoc defensive line to be rapidly built to stave off the invaders. From 1673 on, this defensive line was extended and made into a permanent defence known as the Hollandic Water Line (Dutch: Hollandse Waterlinie).

The first Hollandic Water Line ran from the Zuiderzee to the Biesbosch. The concept was simple, but highly effective. Areas of the country were allowed to flood, preventing enemy advances. Soldiers and equipment were unable to cross land flooded to a depth of approximately half a metre (1½ ft) and stretching a distance of 3 to 5 km (2–3 miles). Elevated areas of land that defenders could not or did not want to flood were defended with fire from forts and strongholds. The primary objective of the water line was to protect the western region of the country, in particular all-important and powerful Holland.

In 1815, on the advice of Cornelius Krayenhoff (Inspector-General of Fortifications), King William I ordered that Utrecht be included in the Water Line. A Utrecht Line was constructed, which combined with the Hollandic Water Line formed the New Dutch Water Line (Dutch: Nieuwe Hollandse Waterlinie).

Many new forts were built between 1816 and 1885 to push the water line farther to the east. Despite these new initiatives, work continued to complete the Old Hollandic Water Line, which then served as a secondary line of defence. The Dutch Fortifications Act (Vestingwet) passed in 1874 determined that the New Dutch Water Line would form part of the Netherlands’ central defence system.

Visit the 1001 Bombs & Grenades exhibition in the castle and stronghold, and bring the New Dutch Water Line to life. Your personal key grants you access to the castle!

The New Dutch Water Line was also based on controlled flooding and water management, only it was more extensive and more manageable than the old water line. An area of polder land 5 km (3 miles) wide could be flooded over a length of 85 km (53 miles) from Muiden to Werkendam. The line also comprised forts and batteries to protect water-control structures and inlets, and to close areas that were not designed to be flooded.

Existing forts were modernized and fitted with bomb-proof bunkers. It was as part of this modernization programme that the casemate (a fortified chamber in the castle’s ramparts) was built at Loevestein in 1882–83.

The New Dutch Water Line was never actually put into operation, although it was prepared for defensive action on three occasions – during the Franco-Prussian War (1870), during World War I and during mobilization in 1939 at the onset of World War II.

After World War II, the Water Line ceased to have any major military significance. Loevestein’s role as a military stronghold finally came to an end by Royal Decree on 18 October 1951. Fortunately, it still stands for all to enjoy as a listed building and a historic testament to the defence of the Netherlands.