Casino Royale was a welcome return to a harder edged Bond that had been absent for years, and although the casting of Daniel Craig in the starring role initially brought with it a huge amount of venomous criticism, his portrayal of 007 was almost universally lauded and the film received an unexpectedly positive response from film critics worldwide.
Part of the problem with James Bond movies for years is that they have been unrealistic and using comedy elements that detract from the tension created by the action and dramatic aspects of the screenplay. It wasn't always so, because Seain Connery's Bond was played seriously, although he had a good stock of one-liners.
Gradually however, this was replaced by out and out comedy, most noteably in Diamonds Are Forever, although creeping in two films earlier in You Only Live Twice.
By the time Roger Moore was cast in the role the plots had discarded any elements of Ian Fleming's stories and replaced them with fantasy. But what was most unforgivable was turning James Bond into a clown. Despite assurances from the producers that Bond would become more serious, many comedy elements remained.
Timothy Dalton was widely considered to be the closest actor to Fleming's Bond, but even in his two films the comedy remained. And when Pierce Brosnan took over things continued - big action pieces, but far to many moments that were simply stupid and there to get a cheap laugh.
With Casino Royale the producers must have realised that they needed to change a tired formula. While the temptation to continue must have been strong - after all, the Bond films always make money - they eventually decided not to continue with Brosnan and follow a new path, going back to Bond's roots in Casino Royale and pick an actor who was a long way from many people's first choice.
They didn't merely get away with it though. The film is widely considered to be among the best James Bond films and achieved a level of critical success that was unheard of for a Bond movie.
Eva Green played Vesper Lynd in Casino Royale, and wore an Algerian Love Knot necklace throughout. You can learn more at http://www.algerianloveknotnecklace.com