In 1017 Henry II gave large areas of land to Paderborn cathedral and in that way imposed on the Lords of Lembeck an oath of allegiance to the cathedral.

In 1190 the Lords of Lembeck built a defensive tower (called “Motte”), on marshy terrain approximately in the area of today’s north wing of the main castle. These foundations can still be traced within the fabric of the castle. Over the following 450 years the tower was gradually extended into a fortified medieval castle. The site of this castle is roughly where the Schlaun’sche hall is now situated.

In 1526, Bertha of Lembeck, daughter of John of Lembeck, married Bernhard von Westerholt from neighbouring Vest Recklinghausen.

During the 16th and 17th centuries the region suffered greatly from the ravages of the Spanish-Dutch war (which lasted 80 years) . This war (in Germany the 30 years during war)  left the Westerholt family with such large debts that in 1631 they had to sell their possessions to the Dutch branch of the Westerholt-Hackfurt family. The Thirty Years War ended in 1648 with the Peace of Westphalia signed in Munster.

The Lord of the castle in the late 17th century, Conrad Dietrich von Westholt-Hackfurt, died in 1702. He assumed that the horrors of this war would be a lesson to humanity and that they would never be repeated. Inspired by this hope of lasting peace, in the second half of the 17th century he built the baroque moated castle in its present open form, while at the same time extending it considerably. Instead of fortified walls the visitor now has the benefit of wide views into the surrounding landscape.

This moated castle, located on two islands, is typical of the style of castle building in Westphalia. The buildings on the first island (Vorburg) were used for administrative and agricultural purposes until 1887. On the second island the main castle (Hauptburg) is situated, occupied by the Lords of the time. A southern wing of the main castle was planned but not built. The natural stone cantilevered from the masonry are still visible and are pointers to this building plan. Over the past three centuries, the moat waters and the open views of the beautiful park and surrounding countryside have given this castle its distinctive charm.

In 1708, Maria Josefa von Westerholt married Droste Ferdinand Dietrich Freiherr von Merveldt of Westerwinkel. During the 18th century the Westphalian architect Johann Conrad Schlaun (1695 -1773) added to the exterior and in 1717 designed the Schlaun’sche Hall, a small jewel of baroque architecture. In 1726, on the instruction of the widow of the late Conrad Dietrich Adolph, he also built St Michael’s Chapel, located two kilometres west of Lembeck village.

In 1887 the north wing of the Vorburg, with its two towers, was destroyed by fire. The remains of one of these towers still indicates the location of the former north western boundary walls.

Schloss Lembeck still belongs to the Merveldt family who were ennobled to Reichsgraf in 1726. For the past three hundred years, generations of owners, deeply rooted in the Westphalian tradition, have preserved the castle’s original baroque style. Schloss Lembeck owes its present authenticity to their careful maintenance of this historic building.