One of the best loved movie series of all time and popular with generation after generation of cinema goer are the James Bond movies and the release of Casino Royale last year has shown that the film series remains as popular as ever.

From Sean Connery to Daniel Craig, every actor to have stepped into the shoes of the world's most famous secret agent has his own dedicated followers, and while each actor's films maintain elements that we now associate with the Bond movies, the style of the films has changed radically on several occasions.

The early years

The first two Bond films starred Sean Connery, who remains the most popular actor as James Bond. Physically looking the part, he brought both toughness and a sense of humour to the role, something that the literary character had always lacked. Plot wise these films – Dr No and From Russia With Love – were little different to the books of Ian Fleming, but by the time of the third film, Goldfinger, the filmmakers decided to start introducing over the top gadgets, this time in the form of the Aston Martin DB5 with ejector seat.

After Goldfinger came Thunderball, and although it remained close to the book, it too had a whole host of gadgets, from underwater breathing equipment the size of a cigar tube to a hydrofoil that splits in two.

Fleming abandoned

After Thunderball came You Only Live Twice, but rather than base the script on the book, it was decided to write an original story using Fleming's characters and location. The film is over the top in every way, with more gadgets - including Little Nellie, the autogyro - a less plausible story and an over the top villain. The film was a success although it was also advertised Sean Connery's last outing as James Bond.

On Her Majesty's Secret Service came next, staring George Lazenby as Bond. It was his only time in the role and allegedly difficult to work with, but he decided to retire from the role before On Her Majesty's Secret Service had even been released on the advice of his agent! The film once again returns to Ian Fleming and is the last Bond film to stick rigidly to its literary original.

Comedy Bond

Sean Connery was persuaded to return to the role of James Bond in the following film, Diamonds Are Forever. However, Fleming was again abandoned in favour of an original story that started to see much more comedy, including a huge car chase in which half the Las Vegas police force seemed to be written off.

This comic trend continued with the introduction of Roger Moore as the films slid further away from the spirit of Ian Fleming and a raised eyebrow was all it took for the Bond girl to fall into bed with him.

Live And Let Die, The Man With The Golden Gun and The Spy Who Loved Me became less and less plausible, with sillier gadgets and more laughs, but after Moonraker the filmmakers decided they needed to plant Bond's feet back on the ground.

The result was For Your Eyes Only, probably the best of the Roger Moore Bond movies, playing a tougher, more ruthless 007 with less reliance on gadgets and comedy. Unfortunately this didn't last – Roger Moore's last two films, Octopussy and A View To A Kill, are perhaps the low point in the series.

The Dalton years

Timothy Dalton's debut as James Bond, The Living Daylights, saw a mixture of styles. On one hand the filmmakers wanted to return to the books, although by now all the novel's titles had been used; on the other they just couldn't leave the gadgets and comedy out of the film.

The result was a film that was head and shoulders above most of Roger Moore's films, but would have been be even better if the moments of stupidy had been left out. One scene that springs to mind is when Bond fires two missiles from his Aston Martin to destroy a truck in his path followed by a scene when the car enters a wooden shed, which he then drives about on a frozen lake. How Ian Fleming would have turned in his grave.

Dalton's second and final film was License To Kill. Bond fans tend to be polarised into loving or hating it, and although the title is original some of the scenes were taken from the book Live And Let Die. Bond was hard, dark, unsmiling… and boring. Dalton's contract was for three movies, but the series was put on hold while the producers went to court over a rival Bond series and when they were ready to film again Timothy Dalton decided not to continue.

The shadow of Roger Moore

Pierce Brosnan's Bond was introduced in Goldeneye, which abandoned the dark side of Bond for what some people have dubbed "Roger Moore-lite". With gadgets and humour, the films are a long way from Ian Fleming although it should be noted that his third film, The World Is Not Enough does include some elements from the books. Tomorrow Never Dies, the second film, is instantly forgettable and Die Another Die, while reasonable good in the first half, has too much science fiction, including an invisible car.

A return to Fleming

After Die Another Day the producers saw that the series needed a shot in the arm and looked to move the next film in a different direction. One of the results of the court action was that they had the rights to make Casino Royale, the original James Bond book to which Ian Fleming had sold the film right independently to the other titles. Deciding to reboot Bond they released that they'd need a younger actor, eventually picking Daniel Craig for the part.

Although Daniel Craig attracted much criticism when filming began, he confounded all but his harshest critics and turned the film into a huge box office success. Bringing a physicality that had been missing since Sean Connery hung up his shoulder holster, Casino Royale drops most of the gadgets and all but the subtlest of humour; the film effectively brings Bond back to his roots and while the story has been expanded from the book, there is much that is faithful to Ian Fleming.

Brosnan's films saw the pre-title sequences (PTS) getting longer and longer – around 20 minutes in Die Another Day – which are just too long, especially compared with what many consider to be the classic PTS in Goldfinger - but in Casino Royale it seems much too short, leaving you wanting more.

From Dr No to Casino Royale, the James Bond series has been phenomenally successful and despite changing with the times and to suit the actors, it appears to have turned full circle. With Bond 22 currently in the planning stages we can only wait and see what the next instalment in the saga holds for us.