A decade later, “Nicholas and Alexandra” was published to acclaim. Though nearly 1,000 pages long, it sold more than 4.5 million copies and is regarded as one of the most popular historical studies ever published.

In Mr. Massie’s account, Nicholas comes across not as stupid, weak or bloodthirsty, as he had been portrayed elsewhere, but as a worried parent.

Robert and Suzanne Massie in 1975 addressed their son’s illness and how it had affected their own lives in “Journey,” a book they wrote together. Some reviewers saw their willingness to discuss deeply personal matters as a deliberate effort to draw a contrast to the Romanovs’ secretiveness and withdrawal.

In reading up on Russian history in his research for “Nicholas and Alexandra,” Mr. Massie became fascinated by Peter the Great, who had dragged feudal Russia toward modernity and turned a swamp into one of Europe’s most beautiful cities, naming it after himself.

But by his account Mr. Massie could not find a biography that captured him. So he resolved to write one. “Peter the Great: His Life and World” (1980), enlivened with anecdotes about Peter’s love for his mistress, Catherine, won the 1981 Pulitzer for biography.

It is the compelling tale of how a man became a legend. Mr. Massie ended the book with a final comment on Peter: “How does one judge the endless roll of the ocean or the mighty power of the whirlwind?”

Image Mr. Massie became fascinated by Peter the Great but, by his account, could not find a biography that captured him. So he wrote one himself.

Deciding that he “had done enough about Russia,” Mr. Massie turned next to naval history, which had captivated him when he was a Navy nuclear targeting officer in the early 1950s. The resulting book, published in 1991, was “Dreadnought,” a 1,000-page history that explores the naval rivalry between Britain and Germany as a means of examining Europe’s drift toward World War I. (The title refers to the battleship of that era, intended to render all other naval vessels obsolete.)