From the page to the big screen: How Hollywood adapted Tom Clancy’s novels

This 2010 image released by G.P. Putnam Sons shows author Tom Clancy in Huntingtown, Md. Clancy,. (G.P. Putnam Sons / David Burnett)

Tom Clancy, the bestselling author who died Tuesday at age 66, was known for his military thrillers and memorable characters.

Many people who never read Clancy’s books were still able to immerse themselves in his stories on the big screen.

Four Hollywood movies were based on Clancy’s novels – all of them revolving around the recurring fictional CIA hero Jack Ryan.

The Hunt for Red October

Clancy’s first novel introduces us to the character of Jack Ryan, a CIA analyst drawn into the hunt for the “Red October” – a high-tech Russian submarine – after it goes off the radar in the middle of the Atlantic Ocean.

The plot centres around a Soviet Navy submarine commander who wants to defect to the U.S. on the Red October and Ryan’s efforts to determine whether that’s just a ruse to allow the Russians to enter American waters.

Like Clancy himself, Ryan is a former insurance broker who grew up in Baltimore.

The book, released in 1984, was turned into a movie in 1990, featuring Alec Baldwin as Ryan.

Sean Connery stars opposite Baldwin as the Russian sub captain, Marko Ramius. A host of other action stars appear in the film, including Scott Glenn, Sam Neill, James Earl Jones and Tim Curry.

The Hunt for Red October won an Oscar for best use of editing for sound effects.

Patriot Games

Patriot Games sees a semi-retired Ryan foil an assassination attempt on a member of the Royal Family while on a family vacation in England. But Ryan’s courageous act draws the ire of the terror group behind the attack after he kills one of its members.

Ryan – played by Harrison Ford in the film version – rejoins the CIA after he realizes the terror group, a splinter faction of the IRA, is going after his family.

The film marked a dramatic departure from the novel’s plot: Clancy’s book is intended to pre-date The Hunt for Red Octoberby introducing us to how Ryan is first drawn into the CIA.

The terrorists’ targets were also changed: Clancy’s novel has Jack Ryan saving the Prince and Princess of Wales (along with their firstborn), while the film sees him save a distant cousin of the Queen Mother.

The film’s final scene also doesn’t appear in the novel at all.

Clancy reportedly distanced himself from the film after reading the script, saying it bore little resemblance to his own words.

While slightly less successful at the box office than The Hunt for Red October, Patriot Games spawned a sequel: Clear and Present Danger, in which Harrison reprises Ryan’s role.

Patriot Games also stars Samuel L. Jackson and Sean Bean, and introduces us to a young Thora Birch -- who plays Ryan’s daughter Sally -- in one of her first feature films.

Clear and Present Danger

In the third film in the series, the beloved Jack Ryan is appointed acting Deputy Director for the CIA after his colleague falls ill. He is immediately thrust into a high-profile case after a close friend of the president is murdered, with all signs suggesting the work of a Colombian drug cartel.

Ryan and another CIA deputy director are given permission to do whatever it takes to take down the cartel and a dangerous covert operation begins.

Clear and Present Danger introduces us to another of Clancy’s famed characters, John Clark. Clark is a CIA officer who was previously known as John Kelly, but had to adopt a new identity after killing drug dealers who tortured and murdered his girlfriend. In Clear and Present Danger, Clark is played by Willem Dafoe.

(The character of Jack Ryan is mentioned in 16 of Clancy’s books, while John Clark appears in 11.)

Sum of all fears

Ben Affleck becomes the new Jack Ryan in this 2002 political thriller.

Ryan, portrayed as a young CIA analyst, is thrust into a terrorist plot by a Palestinian group and an East German physicist to detonate a nuclear bomb during the Super Bowl and make it look like the Soviets were responsible for the attack.

The terrorists’ goal was to start a nuclear war between Russia and the United States, but Ryan manages to contact the Soviet president and diffuse the situation.

The majority of Sum of All Fears was shot in Montreal.

Clancy’s John Clark also appears in the movie, serving as Ryan’s driver and personal bodyguard. The role is played by Liev Schreiber.

Jack Ryan: Shadow Recruit

The Jack Ryan film series will return this year, when Star Trek actor Chris Pine takes over the title role.

Jack Ryan: Shadow Recruit marks the first original film in the series, meaning it’s not based on a Clancy novel.

The film is expected to explore the origins of Ryan as a young CIA analyst. Ryan is paired up with a mentor, played by Kevin Costner, and the pair uncovers a Russian plot to crash the U.S. economy via a terror attack.

It also features Keira Knightly and James Earle Jones, and is set for release on Christmas Day.

The film's trailer will be released tomorrow.