These men helped make 007 one of the most famous secret service agents on the big and small screens.

When author Ian Fleming began writing his first novel, Casino Royale, in 1952 about a fictional British spy agent named James Bond, he could hardly have foreseen the pop culture and media juggernaut that his character would come to be.

While Bond has been depicted in Fleming's novels, as well as short stories, radio, comic strips and more, he really became a force of nature when he started appearing on the small and big screens, with the latter boasting more than 20 films. Five decades later, Bond is still alive and edgy as ever.

In celebration of "Bond, James Bond," here are the actors who brought him into the world of television and film:

Barry Nelson

Barry Nelson as James Bond

Barry Nelson as James Bond in the TV show 'Casino Royale'

Barry Nelson built his acting career as a huge Broadway star before he decided to take on the role of Bond, albeit a "sexless and glum" version dressed in a "crooked bow tie," observed the Los Angeles Times. Nelson was the first to introduce Bond to the world on screen, and he made his debut through a live TV adaptation of Casino Royale on CBS' anthology series Climax! Nelson was the only American Bond (known as Jimmy Bond), and he was well-received by audiences when the show aired in 1954.

Looking back at his portrayal compared to that of his successor Sean Connery, who's credited as putting Bond on the map, Nelson said, "I don't spend much time regretting [my role]. I always thought Connery was the ideal Bond. What I did is just a curio."

Sean Connery

Sean Connery as James Bond

Sean Connery as James Bond in 'From Russia With Love'

Eight years after Nelson's 007 hit television, Sean Connery signed on to transform the role of Bond, turning the MI6 agent into a big-screen hotshot with charisma and sophistication, starting with the film Dr. No in 1962. Fleming was so impressed with Connery's Bond that he wrote his subsequent novels closer to the actor's personality and background. For many fans, Connery's portrayal of the British agent is viewed as the quintessential Bond.

Bond would ignite Connery's career, and he would go on to portray him in six more films, although his 1983 reprisal in Never Say Never Again remains controversial because it was made outside of EON Productions, which was known for producing the film franchise.

Regardless, Connery will be remembered for bringing the character onto the international stage and charming audiences with his martinis "shaken, not stirred."

David Niven

David Niven as James Bond

David Niven as James Bond in 'Casino Royale'

After Connery took a break from the role in 1967, actor David Niven took his place in Casino Royale, a satirical take on Fleming's 007. Although producer Charles K. Feldman had originally wanted EON Productions to develop the film, negotiations fell through, thus making fans view the film as an anomaly to the franchise. Considered himself as an unusual choice to play Bond, Niven depicted the character as a no-nonsense, strategic (yet still classy) spy who could see past the charms of the ladies.

Fleming originally modeled his Bond character after Niven, but considering the actor was getting up there in his age, he never had the chance to reprise his role.

George Lazenby

George Lazenby as James Bond

George Lazenby as James Bond in 'On Her Majesty's Secret Service'

Another interesting choice for Bond was that of Aussie model-turned-first-time-actor George Lazenby, who starred as the British agent in 1969's On Her Majesty's Secret Service. Although opinions vary widely on Lazenby's performance, critics agree that the tone of the film matched most closely to Fleming's novels. Still, the film made some odd choices that stand out from other Bond films, including the use of only one large gadget and that Lazenby's Bond had a female sidekick.

Despite the project doing well at the box office (although not nearly as impressive as Connery's last two Bond films), the newly minted actor never got his career off the ground nor did he ever reprise the role of Bond in a major motion picture again. Not only did Lazenby reportedly have difficulties getting along with his co-stars and director Peter R. Hunt, but his manager also did him a disservice by convincing him not to sign a seven-film contract since, according to him, the Bond character was an archaic role to play. 

Roger Moore

Roger Moore as James Bond

Roger Moore as James Bond

Incorporating safari suits and Cuban cigars to the role, Roger Moore brought a charming tongue-in-cheek playboy vibe to Bond like never before. Although he was in talks to play the British spy agent early on, he finally got to make his mark in Live and Let Die (1973) and would eventually be the Bond actor to tie Connery with the most longevity (each man starring in seven films total).

Moore's interpretation of Bond was the furthest from Fleming's vision, as he was known for bringing humor and absurdity to 007, but that's what makes some fans and critics view him as the most interesting Bond of all.

Timothy Dalton

Timothy Dalton as James Bond

Timothy Dalton as James Bond in 'The Living Daylights'

Believe it or not, before Timothy Dalton starred in two installments of the franchise The Living Daylights (1987) and Licence to Kill (1989), he was in the running to play Bond way back in 1967 when he was just 21 years old. Understandably, though, he was thought too young for the role and was temporarily set aside.

Fast forward to the late '80s, and Dalton — a classically trained Shakespearean actor by trade — finally had his chance, but unfortunately, his two films ended up being largely forgettable. Dalton's Bond was serious, cold and focused, just the way Fleming had created him in his novels, yet audiences weren't taken with him or the storylines, resulting in a tepid response at the box office. Still, some critics argue that Dalton offered a strong interpretation of Bond.

Although the actor was slated for a third film, legal troubles regarding licensing prevented production from moving forward, and he was compelled to take on other projects.

Pierce Brosnan

Pierce Brosnan as James Bond

Pierce Brosnan as James Bond in 'GoldenEye'

Like Dalton, Pierce Brosnan was considered to play 007 earlier on in his career but didn't get his chance until the 1990s, starting with Goldeneye (1995), which ended up being a commercial hit. Brosnan brought Bond into a new post-Cold War era and added his own personal touches to the role (his Bond didn't smoke and he treated his female counterparts as equals).

Mixing traits of Moore and Connery's Bonds, Brosnan was able to offer a successful balance of humor, charm and edge to his character, and audiences loved it. The actor went on to reprise his role three more times — Tomorrow Never Dies (1997), The World Is Not Enough (1999), Die Another Day (2002) — with great box office success.

Although he considered having a go with Bond for a fifth time, he ultimately passed the torch, allowing a fresh new face to enter the canon.

Daniel Craig

Daniel Craig as James Bond

Daniel Craig as James Bond

James Blonde, anyone? Fresh and new weren't necessarily the first words that were coming out of the mouths of Bond fans when they found out that Daniel Craig was embodying the British spy agent. Many fans complained Craig didn't fit the character's description of tall, dark and handsome and subsequently mocked the stage-trained actor, calling him names like James Blonde and James Bland. But Craig would prove them wrong.

Like Brosnan, Craig brought Bond into a new era — this time, the 21st century. His Bond returned to Fleming's original vision, along with the best traits of previous Bonds before him. Craig brought edge, charisma and vulnerability to the role, invariably winning wary fans over.

His debut in 2006's Casino Royale was a huge success, and he continued his role in three more films — the last thus far being Skyfall (2012), which ushered Bond into his fifth decade. Craig will also star in 2020's Bond25, the 25th installment of the franchise.