Prince Ernst August of Hanover is suing his son for selling their family castle for $1

• Prince Ernst August of Hanover is suing his son of the same name for selling Marienburg castle.
• The castle was sold for $1.20 to the German government, which pledged $16.5 million for renovations.
• Ernst August Jr. was gifted the property and surrounding Calenburg estate in the mid-2000s.

Prince Ernst August of Hanover is suing his son of the same name for selling a castle to the German government for $1.20 (€1).

Christian Rickens, an editor at German newspaper Handelsblatt Today, reports that the father and son are feuding over Marienburg castle and the surrounding Calenburg estate, which are said to be run-down and in need of $32.8 million (€27 million) worth of renovations. This meant that upkeep for the 135-room Gothic creation in Lower Saxony made it a financial burden for the house of Hanover, rather than an asset.

Unhappy with what he called his son's "gross ingratitude," according to a court statement published on the Hanover Regional Court website on Tuesday, Ernst August Sr. began his legal battle to win back the property and other assets at the end of 2020. He filed the lawsuit with Hanover Regional Court through a Berlin law firm.

It adds that the 66-year-old German prince, who is the estranged husband of Princess Caroline of Monaco, gifted his son, 37, a total of three properties between 2004 and 2007 "by way of anticipated succession."

Handelsblatt Today also reports that Ernst August Sr.'s senior lawyers sent a 32-page legal letter to government headquarters and to the state premier of Lower Saxony, Stephan Weil, last week.

According to the court statement, he alleges that Ernst August Jr. has gone "behind the back of his father" to seize control of the property and that his decision to sell the castle to the German authorities for a symbolic €1 "seriously violated [Ernst August Sr.'s] rights, legal entitlements, and interests."

It states that Prince Ernst August Sr. further alleges that his son "appropriated works of art and antiques" from the Herzog August Library in Wolfenbüttel and from the Hanover Historical Museum. The artifacts, including "paintings, historical carriages, and a collection of sculptures," have now been donated to Hanover's state museum, according to the court statement.

The Hanover royals are distant relatives of Queen Elizabeth II. Their lineage is linked to the Welfs, a European medieval dynasty also known by the title "the Guelphs."

Prince Ernst August Jr. wants the assets to be enjoyed by the German public, according to The Local. The publication reports that Ernst August Jr. told German news agency DPA that the sale will ensure that the castle, which invites 200,000 visitors each year, is preserved for public access. Ernst August Jr. also told DPA that the arguments raised in the lawsuit "have already been invalidated out-of-court in the past," The Local reports.

Germany's federal parliament, Bundestag, has pledged $16.5 million (€13.6 million) into renovations for the monument and the young prince also confirmed to DPA: "There's nothing that stands in the way of the long-term preservation of Marienburg as a central cultural monument of Lower Saxony, open to all."

It is not yet known when the case's oral hearing will take place.

Insider was unable to reach representatives for Prince Ernst August of Hanover Jr. and Sr. for comment.