The castle was probably built around 1100 by the Dutch Count of Zutphen to protect the important trade route from Lübeck via Bremen and Münster to Cologne, in order to be able to control this narrow and easily visible place and to be able to demand customs duties.

Count Symon received Tecklenburg Castle as a fiefdom and gave his allods for 50 marks to the Archbishopric of Cologne.

But in 1400, he lost the northern parts of the county with the districts of Cloppenburg, Friesoythe and Bevergern to the Prince-Bishopric of Münster.

In 1400, during the rule of Count Nicholas II, Tecklenburg lost its northern territory in a conflict with the Bishopric of Osnabrück.

This, and the fact that the Bremen-Cologne trade route was being re-routed more and more via Osnabrück with its now upgraded trunk road, reduced the strategic importance of Tecklenburg.

Weapon technology had also changed significantly in the meantime, and the outdated defensive systems of Tecklenburg could only be improved very slowly.

In 1547, Conrad took part in the Battle of Mühlberg, in which the Protestants were defeated by the Catholics under Emperor Charles V. During this phase of the conflict, the defensive strength of the castle was greatly expanded because attacks were always expected.

From there, fire could be brought to bear on the southeastern moat, the market square, the valley to the north and the northwestern side of the castle.

The outer windows were enlarged and a new access, today's Schlossstrasse, was constructed to reach the new north-eastern entrance to the castle.

All of this resulted in the Tecklenburg losing much of its defensive strength, and a large part of the bastion was buried by the embankment on which Schlossstrasse was built.

Over time, the bastion fell into obscurity and was only rediscovered by chance in 1944, when a large cavity was found while digging an air raid shelter.

The county of Tecklenburg went to Arnold II (IV) of Bentheim-Tecklenburg in 1557, bypassing the inheritance claims of the house of Solms-Braunfels.

In 1884, the Wierturm tower was built on the rampart that separated the forecourt from the main castle in memory of court doctor, Johann Weyer, who, with Countess Anna, opposed the burning of witches.

At the end of the 19th century, there were plans to build a large climatic spa hotel on the castle complex, but these were rejected.