NEW YORK — Robert K. Massie, the Pulitzer Prize-winning historian who specialized in best-selling and critically praised biographies of the Russian tsars and discovered a personal connection to the country’s past through the blood disorder that afflicted both his son and the son of Nicholas II, died Monday at age 90.

Son Christopher Massie told The Associated Press that the author, who had been suffering from Alzheimer’s disease, died at his home in Irvington, N.Y.

Likened to David McCullough and Edmund Morris as a popularizer of history, Massie wrote epic page turners on two outsized tsars: the 900-page “Peter the Great,” winner of the Pulitzer in 1981; and the 600-page “Catherine the Great,” winner in 2012 of a PEN award for biography. Reviewing “Catherine the Great” for The New York Times, Kathryn Harrison praised Massie as both a scholar and literary stylist.

Massie’s first book drew upon his interest in Nicholas’ heir apparent, the Tsarevich Alexei, a hemophiliac like the eldest of Massie’s three children, Robert Jr. “Nicholas and Alexandra” was published in 1967, in the midst of the Cold War, and praised in The New York Times as a long-needed and balanced account of the last tsar and his family. Massie’s book also was a commercial success and the basis for a 1971 film adaptation, starring Michael Jayston and Janet Suzman, that won the Oscar for art direction. Massie thought the film superficial, but took advantage of the publicity to raise money for hemophilia treatment.