She was also a younger sister to Prince Heinrich XXIV Reuss of Köstritz and a first cousin to Grand Duchess Maria Pavlovna of Russia.

As a man who was no longer required to produce heirs, Ferdinand stipulated to his assistant that he wanted a bride who did not expect affection or attention.

Eleonore remained neglected by Ferdinand throughout their marriage, leaving her to raise her stepchildren and devote herself to the welfare of the Bulgarian people.

Eleonore came into her own during the Balkans and First World Wars when, working tirelessly as a nurse, she was a cause of great comfort for many injured and dying Bulgarian soldiers.

Tsaritsa Eleonore became seriously ill during the final years of World War I, dying in Euxinograd, Bulgaria on 12 September 1917.