Best-selling author Tom Clancy, creator of the iconic series of espionage and military thrillers starring Jack Ryan, has died at the age of 66. The author passed away at a Baltimore hospital near his home in Maryland late on Tuesday night, according to his publisher.

One of the first reports of his death came from Maryland Twitter user @amscherm, who claimed to be a family friend of Clancy's brother-in-law. Though the story spread around online, it remained a quiet, unconfirmed rumor. This morning, Publisher's Weekly tweeted out the news, and it was then quickly confirmed by Clancy's publisher Penguin to The New York Times book reporter Julie Bosman.

Clancy was best known for his many bestselling spy novels set in a late- and post-Cold War era. In fact, he never wrote a book that didn't reach bestseller status on The New York Times list. He took on a more digital life later in his career, thanks to a collection of third-person shooter video games based on his work and bearing his name, including Tom Clancy's Splinter Cell.

Clancy's first book, The Hunt for Red October, was an instant bestseller back in 1984 for its intensity and its realist, highly detailed portrayal of military technology and espionage tactics, particularly after President Ronald Reagan praised it as a "really good yarn." That novel featured the fictional CIA analyst Jack Ryan as the lead character, a character that would eventually be taken on by Alec Baldwin in the film by the same name. From there, Clancy's books all became top-chart reads, prominently sold on airport bookshelves, and his later Ryan books — Patriot GamesClear and Present Danger, and The Sum of All Fears — all became successful feature-length films. The Ryan character was also portrayed by movie stars Harrison Ford and Ben Affleck, and the series will be getting a film reboot on Christmas this year with Jack Ryan: Shadow One, this time with Star Trek's Chris Pine in the lead role.

As he got older, Clancy's name became its own brand, with dozens of novels and games bearing his name, even though many were written by other others. Even as his films and video games took off, Clancy continued writing both fiction and non-fiction, most recently with the 2012 novel Threat Vector. His last novel, Command Authority, with (now President) Ryan, is expected to be published in December.