In "Daisy, Princess of Pless by herself", Daisy wrote rather undramatically that she believed Adolphus Frederick had been severely depressed because of being torn between his pro-British sympathies and his love of Germany, and the death of his Grandmother Augusta of Mecklenburg-Strelitz (born a princess of Great Britain and a confidante of her niece, Queen Mary) - and because of debilitating hay fever! The latter seems a bit of a stretch (although of course at the time there were few means of alleviating the symptoms and they can be very severe), but the others seem not unreasonable. Daisy herself was very much the target of anti-British accusations in the press and Adolphus Frederick would have been perceived as tarnished by association, not a great leap to accusations of being Daisy's lover and acting under her direction to spy for Britain. From Daisy's various memoirs the anti-British hysteria in the press and German society generally sound very much like those in Britain at the time and could be very wearing after a while, especially if Adolphus-Frederick had lost one of the few confidantes sympathetic to his internal conflicts in his grandmother. Of course being depressed because of a bereavement and press hostility, and feeling ill, is not such a good story as a jealous Kaiser (although I think it was actually his son, Crown Prince Wilhelm, who had rather a crush on Daisy), blackmail, forced divorces, etc.
More on his romantic life:
"While Adolf Friedrich remained unmarried and without a son, there was an issue surrounding the succession, as his heir Duke Karl Michael had indicated to him just before war broke out that he wished to renounce his rights to the Mecklenburg throne. During the war, the topic of his marriage was discussed by Adolf Friedrich and his friend Princess Daisy; however in war time it was difficult to arrange a meeting between Adolf Friedrich and an eligible princess. Eventually, with the assistance of Princess Daisy a match was found. The princess having secured the interest of one of her husband’s distant cousins, Princess Benigna Reuss zu Köstritz and as Adolf Friedrich was agreeable to the match his Minister President Heinrich Bossart began negotiations to bring about the marriage.
Although what appeared to be a simple process that only needed a public announcement so that a wedding date could be set was wrought with unforeseen challenges that to this day are rather sketchy. It seems, before an engagement could be announced there was the complication of a woman that Adolf Friedrich was rumored to have been involved with, and who he was said to have made a promise of marriage to and needed to be freed from before he could make Princess Benigna his wife. The exact true identity of the woman involved is unclear. One woman that has been mooted over the years was the Italian opera singer who Adolf Friedrich had begun a love affair with while Hereditary Grand Duke and who he had invited to his summer residence in 1916 and 1917. From 1908 until his death ten years later, his mistress was the operatic soprano Mafalda Salvatini. An Italian by birth but raised mainly in Paris, she was a star at the Berlin State Opera and the Deutsche Oper Berlin. Supposedly, Salvatini had two sons by Adolphus Frederick, Horst Gérard and the set and costume designer Rolf Gérard. According to Adolf Friedrich’s nephew, Prince Ernst August zur Lippe, Adolf Friedrich was the father of the two boys, although it is not known for certain whether he was indeed the father and Rolf has stated he believes his father was Walter Gérard.
To add further, Adolf Friedrich also had been in a relationship with a Hungarian born woman Margit Höllrigl. While heir to the throne he was reported to have given her a marriage proposal so he would not have to become grand duke and in so doing his brother Duke Karl Borwin would marry and succeed him instead. But the sudden death of his brother in a duel with their brother-in-law, Count Georges Jametel, who had mistreated their sister Marie made it essential for Adolf Friedrich to remain heir and one day marry and continue the dynasty. Faced with this new and unexpected dilemma, he tried to pay Höllrigl off to release him from his promise, but apparently she was in possession of letters linking Adolf Friedrich to homosexual relationships, which would have caused a great scandal and so blackmailed him to extract more money.
With the war entering a fourth year, and his love affairs possibly going to become public knowledge before he contracted his dynastic marriage, on the evening of Saturday, February 23, 1918, Adolf Friedrich left his palace in Neustrelitz to take his dog for a walk. When it was discovered the next morning that he had not returned a search was carried out. Upon the emptying of a small lake on his estate he was found dead with a gunshot wound to his temple, thus bringing about a tragic end to Adolf Friedrich’s four year reign which had been blighted by war and his own personal sadness.
An autopsy found that he had drowned and no weapon was recovered from the scene. The circumstances surrounding his death are still to this day unclear. Rumors surfaced after his death that the German Secret Service had discovered that he had been spying forGreat Britain and that he had been given the choice of being tried as a traitor to the German Empire, or he could take his own life. This story was refuted by his close friend Princess Daisy. Cleary troubled at the time of his death, the catalyst was probably a combination of factors such as the war, his impending marriage and potential scandal caused by his old lovers. Or was it? He was also reportedly suffering from neurasthenia. "
