After graduating from Harvard University in 1972, Bergreen worked in journalism, academia and broadcasting before publishing his first biography, James Agee: A Life.

A frequent lecturer at major universities and symposiums, and, on occasion, aboard cruise ships, he has served as a Featured Historian for the History Channel.

[4] In 2007, Bergreen was asked by NASA to name some geological features surrounding the Victoria crater on Mars, based on places Ferdinand Magellan visited.

Warner Brothers is developing a feature film based on this book starring Matt Damon and written by William Monahan.

[7] In May 2017, Roaring Brook Press, a division of Macmillan, published his first Young Adult book, Magellan: Over the Edge of the World, an adaptation of his international bestseller.

His most recent adult book is the highly acclaimed In Search of a Kingdom: Francis Drake, Elizabeth I, and the Perilous Birth of the British Empire, available from HarperCollins Publishers in March 2021.