“Jack was very much part of the equation. He wanted to travel, and Truman wanted to please him,” said Gerald Clarke, author of the authoritative “Capote: A Biography.”

“But Truman was also pleasing himself. Though he came from a small town in Alabama, he loved New York, loved it so much that he found it hard to write when it was so tempting to go out on the town,” Mr. Clarke told me. “New York was a kind of addiction. He realized that if he wanted to write — and that’s all he wanted to do — he would have to do it elsewhere.”

While Capote would rise to become arguably New York’s greatest literary and social lion of the ’60s, whose iconic Black and White Ball at the Plaza hotel in Manhattan in 1966 would be called the “party of the century,” with boldfaced names from Frank Sinatra to the Maharani of Jaipur mingling behind costume masks , the Capote who bunked in Forio knew his best work could only be done in self-imposed exile.

His time living in the small coastal towns and villages of southern Italy and Spain allowed him to produce a remarkable output that matched his outsized ambition. Last spring and summer, I went in search of these seaside idylls, hoping to retrace a long ago golden boy’s moment in the sun.