Canal of Corbulo

Corbulo's canal today

The Fossa Corbulonis was (and is) a canal between the river Rhine and the estuary of the Meuse.

More precisely, it consists of:

The ancient fort at Matilo, near modern Leiden (map; satellite photo);
Rijn-Schiekanaal (map; satellite photo);
Vliet (map; satellite photo; the peat lakes are recent);
Trekvliet (map; satellite photo);
The ancient city of Forum Hadriani, modern Voorburg (map, satellite photo).

According to Tacitus (Annals, 11.20), the Roman general Gnaeus Domitius Corbuloordered its construction in 47; its purpose was to prevent ships from sailing offshore on the dangerous outer sea, and because the canal made it easier to each the new forts along the Lower Rhine, the project may have belonged to the Claudian army reforms. Ships from the Rhineland could now move to the estuary of the Meuse (the Helinium) in safety; over there, it was easier to transfer cargo to seaworthy ships than at the mouth of the Rhine, at Katwijk. This was especially useful because in these years, many soldiers came from the Rhineland and had to fight in Britain.

A dendrochronological monster from three poles, taken in 2006, showed that the trees were cut in 50, which suggests that there work continued for a long time, or that repairs were needed swiftly after the original construction.

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Corbulo (Louvre)

The Canal of Corbulo was situated on a small strip of land between, on the western bank, the old dunes and the peat moors on the east bank. The capital of the Cananefates, Voorburg, was founded exactly at the watershed between the river basins of Meuse and Rhine.

To maintain the water level, there were dams with spillways. Where necessary, the banks were timbered. Dendrochronological datings of these structures indicate that the canal was improved by the emperor Hadrian, who visited the region in 121. It is possible that there is a connection to other activities in the region, which were commemorated by changing the name of the old Municipium Cananefatium into Forum Hadriani (Voorburg). We should not make too much of the change in the town's name, all the more so because the old name continued to be in use.

Reconstruction of an ancient Roman bridge at Rietvink, Voorburg. Photo Jona Lendering.

The Rietvink bridge (©**)

In 1989, clay deposits (unusual in a region of peat moor) and traces of ancient woodwork were discovered at the new Rietvink quarter of Leidschendam. It was possible to establish that the canal was about three meters deep and fifteen meters wide, enough for two ships. Water lilies, yellow irises, flowering rush, and spiked loosetrifes were along the banks. On the sandy west bank, near the dunes, one could see beeches, oaks, hazels, juniper bushes, herbs, grass and (of course) sea buckthorn.

Since 1993, a modern, Roman-style bridge (inspired by the bridge Julius Caesar constructed across the Rhine) can be seen on the site of the ancient canal at Rietvink. A satellite photo can be seen here.