His maternal grandfather was the poet Vasily Zhukovsky, who was the illegitimate son of a landowner named Afanasi Bunin and his Turkish housekeeper Salkha.

But even if they were married, the marriage was morganatic, because Alexandra was born a "commoner," and not of a royal or formerly sovereign family.

The name was chosen from the village of Belyov in the province of Toula where his grandfather poet was born.

Count Alexei married, on 29 August 1894 in Ilyinskoye manor [ru], Princess Maria Petrovna Troubetskaya (18 June 1872 Russia – 20 March 1954 Paris), the daughter of Prince Petr Troubetskoy.

As Ilyinskoye was the property of his uncle the Grand Duke Sergei, Governor of Moscow, it can be taken as a sign that he was quite accepted in Imperial circles (and he served as Serge's orderly since 1904).