[1] In 1942 Spangen Castle was excavated, because an inland harbor for Rotterdam would be constructed in the area.

The excavation was led by Jaap Renaud of the Rijksdienst voor de Monumentenzorg.

The idea was probably to first defend the court side only with an earth breastwork along its moat, and to extend the stone structure later on.

[5] The court side corner of the tower house had a wide protruding foundation.

[5] In the second construction phase a stone wall was built around the court, see map XIVB and Oorspr.

[5] The gate had two openings on the moat side (see map), probably for heavy beams that were part of the draw bridge.

[6] East of the gate a small stretch of an enceinte started, showing its character by the buttresses that supported a protected walkway.

[6] The third construction phase (XVB) started by filling the northeast and southeast part of the moat.

On its northwest and northeast side the wing had a new heavy cavity wall, a very rare concept in medieval times.

On the southern tip of the new wing was a high stair tower, displayed on many pictures of the (ruined) castle.

Renaud therefore dug a trench under the northeast wing, which indeed confirmed that it stood on top of a former moat.

[6] A shoring had been built about half a meter outside of the foundations in order to give some stability to the filled up area.

The archaeologist Jaap Renaud was quite fond of describing the different types of brick he found at castles.

[8] The first known ancestor of the lords of Spangen Castle was Philips Uytter Nesse.He was married to Sophia van Dorp, and mentioned in 1307.

In 1309 Philips (Voernesse) is included in the verdict of the killing of Wolfert van Borselen at Delft in 1299.

In 1323 Dirk Bokel was granted in fief 47 morgen of land on the small river Spange by Sir Gerard van Heemskerk.

[11] Jan van der Spangen was probably rather poor, and dependent on serving the count for income.

[15] Symon van der Sluys therefore claimed that Spangen Castle had been destroyed by the Cod party in 1351.

[16] Others claim that none of the Hook castles in the area was besieged, and that they were simply handed over and demolished without a fight.

Renaud also mentioned that Dirk might have drawn conclusions from what happened at Te Riviere, and quickly switched to the other side.

The idea that Willem Nagel destroyed Spangen Castle would be illogical, because Egbert was on Jacqueline's side.

[21] During the opening phases of the Eighty Years' War, the Van der Spangen family would move to the Southern Netherlands.

The artist and architect Jacob Lois (c. 1620–1676) [23] made several drawings, and even a more or less accurate floor plan of the castle in 1670.

[24] These drawing seem to have been used by F. Baudouin to make the double engraving showing the castle in prosperity and in ruins.