NEW YORK (AP) ― Tom Clancy, whose high-tech, Cold War thrillers such as “The Hunt for Red October” and “Patriot Games” made him the most widely read and influential military novelist of his time, has died. He was 66.

Penguin Group (USA) announced that Clancy had died Tuesday in Baltimore. The publisher did not provide a cause of death.

Tall and thin, with round, sunken eyes that were often hidden by sunglasses, Clancy had said his dream had been simply to publish a book, hopefully a good one, so that he would be in the Library of Congress catalog. His dreams were answered many times over.

His novels were dependable best sellers, with his publisher estimating that worldwide sales top 100 million copies. Several, including “The Hunt for Red October,” “Patriot Games” and “Clear and Present Danger,” were later made into blockbuster movies, with another based on his desk-jockey CIA hero, “Jack Ryan,” set for release on Christmas. Alec Baldwin, Ben Affleck and Harrison Ford were among the actors who played Ryan on screen. The upcoming movie stars Chris Pine, Keira Knightly and Kevin Costner, with Kenneth Branagh directing.

A political conservative who once referred to Ronald Reagan as “my president,” Clancy broke through commercially during a tense period of the Cold War, and with the help of Reagan himself. In 1982, he began working on “The Hunt For Red October,” basing it on a real incident in November 1975 with a Soviet missile frigate called the Storozhevoy. He sold the manuscript to the first publisher he tried, the Naval Institute Press, which had never bought original fiction.

In real life, the ship didn’t defect, but in Clancy’s book, published in 1984, the defection was a success. Someone thought enough of the book to give it to President Reagan as a Christmas gift. The president quipped at a dinner that he was losing sleep because he couldn’t put the book down ― a statement Clancy later said helped put him on the New York Times best-seller list.

Clancy was admired in the military community, and appeared ― though he often denied it ― to have the kind of access that enabled him to intricately describe anything from surveillance to the operations of a submarine. He often played off ― and sometimes anticipated ― world events, as in the pre-Sept. 11, 2011 paranoid thriller “Debt of Honor,” in which a jumbo jet destroys the U.S. Capitol during a joint meeting of Congress.