It is already conceivable that in Roman times there was a military base at this point, high above the Rhine, halfway between Xanten and Nijmegen.

[1] The knight's hall, built around 1170, stood where today the car park surrounded by lime trees is located in the outer courtyard.

Significant amounts of his original plan for Kleve were put into effect and have been maintained to the present, a particularly well-loved example of which is the Forstgarten.

Wolfram's story is a variation of the Knight of the Swan tale, previously attached to the Crusade cycle of medieval literature.

Members of this order are sent out in secret to provide lords to kingdoms that have lost their protectors and Loherangrin is eventually called to this duty in Brabant,[citation needed] where the duke has died without a male heir.

His daughter Elsa fears the kingdom will be lost, but Loherangrin arrives in a boat pulled by a swan and offers to defend her, though he warns her that she must never ask his name.

From Dutch legends of the Swan knight we read that Dietrich, Count of Cleves, Lohn in Westphalia and Teisterbant died in 713 and his daughter Beatrix had to succeed him.

According to one of these sources to 711, a daughter of a noble family named Beatrix married a Count Aelius (or Helios) Gralius, who was a follower of Charles Martell.

A "Beatrix" from a noble house is also mentioned in a legend or fairy tale as the ancestor of the Counts of Cleves, who married a swan knight Elias.

Their daughter and heiress Beatrix, Countess of Teisterbant, got married after the death of both her parents to Elias, Aelius, or Elius Grail, Gralius, Graielis, or Grajus, a great hero, Stadtholder of Nijmegen and (purely legendary) first Count of Cleves.