The Grand Duke was a supporter of the liberal (sometimes referred to as "enlightened") bureaucrats during the period of his brother Alexander II's great reforms.

The Geographical Society was subordinate to the Ministry of Internal Affairs, which was home to a conspicuous number of liberal bureaucrats [ru], including Nikolai Miliutin.

Konstantin had five illegitimate children with his mistress Anna Kuznetsova (1847–1922); they bore the last name Knyazev: Konstantin was the paternal great-great-grandfather of King Charles III of the United Kingdom, since his daughter Olga married George I of Greece, whose son Andrew married Princess Alice of Battenberg, and they became the parents of Philip, Charles' father.

Through Constantine I of Greece, another son of Olga and George I, Konstantin is also the paternal great-great-grandfather of Queen Sofía of Spain, mother of King Felipe VI.

In the book, Konstantin is the brains behind the liberal reforms of his brother, Russian Emperor Alexander II, as well as the sale of Alaska to the United States.