In 1980, at the age of 36, Lichtenberg was adopted as an adult by deposed German royal Marie-Auguste of Anhalt (1898–1983), whose first husband was Joachim, son of former German Emperor Wilhelm II. Upon adoption, Lichtenberg's name became "Frédéric Prinz von Anhalt", although "Prinz" is part of the legal surname and not a princely title. Since 1919, former royal and noble titles in Germany, which were all abolished then, may only be used legitimately as part of registered, legal Surnames. Nevertheless, Anhalt styles himself "Prince Frédéric of Anhalt, Duke of Saxony and Westphalia, Count of Ascania". Some reports state that Anhalt claims to have been a childhood friend of Marie Auguste's only child, Karl Franz (1916–1975), and that the grieving mother adopted him out of kindness, calling him "Prince" and "Duke of Saxony". However, British press reports indicate that Marie Auguste was bankrupt and the adoption was a Business transaction, allegedly masterminded by Hans Hermann Weyer, a former window dresser who became the honorary consul of Bolivia in Luxembourg. Weyer was known for selling certificates of nobility, doctoral degrees from fictitious universities, and other spurious decorations in Germany in the 1960s. Lichtenberg was one of about 35 adults adopted by the ex-princess, some then styling themselves Princes of Anhalt.

In 1984, Anhalt moved to the U.S., becoming a socialite and living a flamboyant lifestyle. On August 14, 1986, he married Hungarian-born American Actress Zsa Zsa Gabor, who was 26 years his senior. It was his seventh marriage: he had married and divorced six times before, on one occasion receiving a settlement of $4 million.

At the time of her death, relations between Hilton and von Anhalt had been sour for nearly a decade. In 2005, he sued Hilton, alleging she had attempted to defraud her mother. However, Gabor refused to sign the papers in her husband's suit against her daughter so the court dismissed it.

On July 25, 2007, while sitting in his Rolls-Royce in Southern California von Anhalt was allegedly approached by three women whom he later described as attractive. He said they asked him to pose for pictures with them, at which point one of the women robbed him at gunpoint, taking his car keys, jewelry, wallet, driver's license, and all his clothes. According to Anhalt, his assailants bound him and placed him in handcuffs, yet he managed to call the authorities on a cellular phone. Los Angeles police found him completely naked approximately one hour later. No handcuffs were found at the scene. The culprits apparently drove away in a Chrysler convertible.

On October 20, 2010, Anhalt was taken to a hospital after swallowing a bee, which then stung him in the throat. On December 22, 2010, he was again admitted to a hospital after gluing his eye shut with nail glue. On September 2, 2011, he was hospitalized after being hit by a car in Beverly Hills.

In October 2011, he announced his candidacy for Mayor of Los Angeles in the 2013 election. He announced via a large billboard on Sunset Boulevard. He did not pursue this campaign, and did not appear on the ballot.

Since the death of Gabor in December 2016, von Anhalt has inherited her Bel Air mansion and all of her assets as the sole remaining heir. Anhalt claims that Gabor’s late daughter, Francesca Hilton, stole Gabor’s will while she was hospitalized, but due to her death in January 2015, it did not interfere with Anhalts acquisition of her assets.

On September 18, 2017, Anhalt again announced his candidacy for Governor of California, this time in the 2018 election.