In later years, Botkin became a lifelong advocate of Anna Anderson, who claimed to be the surviving Grand Duchess Anastasia Nikolaevna of Russia.

Gleb was born on 30 July 1900 in Ollila, Hyrynsalmi Municipality, Kainuu, Finland (at the time a ducal province of Russia).

[citation needed] His parents divorced in 1910, when Botkin was 10, due to his father's demanding position at court and his mother's affair with his German tutor, Friedrich Lichinger, whom she later married.

He used to amuse the grand duchesses on holidays and when they were all in exile at Tobolsk with his stories and caricatures of pigs dressed in human clothing acting like stuffy dignitaries at court.

[citation needed] Botkin was described by one historian as "articulate, sensitive, with pallid skin and soulful green eyes" and as "a talented artist, a wicked satirist, and a born crusader".

[5] His obituary in the New York Times called him "a tenacious champion [of Anna Anderson's] fight for recognition as Anastasia" and a "devoted monarchist".

He married Nadezhda Mandrazhi-Konshina, widow of Ensign of the Dragoons regiment, nobleman Mikhail Nikolaevich Mandrazhi, who was the chevalier of the Order of Saint George and was killed in battle in June 1915 at Grodno in Belarus.

Historian Peter Kurth wrote that Botkin tended to overlook some of the more unattractive aspects of Anderson's personality, such as her stubbornness and rapid changes in mood, or to view them as manifestations of her royal heritage.

"She was, to Gleb's way of thinking, an almost magically noble tragic princess, and he saw it as his mission to restore her to her rightful position by any means necessary", wrote Kurth in Anastasia: The Riddle of Anna Anderson.

[13] Anderson never joined his church but did not object when Botkin finished his letters to her with this prayer: "May the Goddess bestow Her tender caress on Your Imperial Highness's head.

"[13] Botkin had argued his case before the New York State Supreme Court in 1938 and won the right to an official charter for the religion.

[14] Botkin held regular church services in front of a statue of Aphrodite, the ancient Greek goddess of love, and presided over them dressed in the regalia of an archbishop.

[15] Botkin told a reporter for The Cavalier Daily, the student newspaper at the University of Virginia at Charlottesville, that his religion pre-dated Christianity.

[17] His daughter Marina Botkina Schweitzer's DNA was later used to help identify the remains of her grandfather, Yevgeny Botkin, after they were exhumed along with those of some of the Romanovs in 1991 from a mass grave discovered in Ganina Yama near Yekaterinburg.