After At World's End , the Pirates franchise may not have been the critics' choice, but there was no denying its audience-snaring potential.
After plundering the box office to the tune of $2.5 billion over three installments, Part IV seemed inevitable.
At Disney's D23 expo in 2008, a fully-costumed Depp announced that the fourth installment was in development, though there were no real details (save for Depp's apparent involvement) at that time.
Rumours abounded: would this be The Jack Sparrow Show, an adventure in the vein of Indiana Jones , or would Depp be passing on the baton to another actor who would carry the series in the future?
Then the unimaginable came very close to happening, as Disney Chairman Dick Cook handed in his resignation, and Depp's involvement seemed uncertain.
It was Cook who had got Depp involved in the franchise initially.
Speaking to the LA Times, the actor recalled the first time Cook mentioned the project to him: "I said I was in. That was before there was a script or anything."
Depp played tribute to Cook as "instantly trustworthy... He's a rare beast."
On his 'unusual' performance (considering he was carrying a summer blockbuster on his shoulders), Depp said: "When things went a little sideways on the first Pirates movie and others were less than enthusiastic about my interpretation of the character, Dick was there from the first moment."
"He trusted me... [He] was completely supportive of me."
The actor went on to say: "There's a fissure, a crack in my enthusiasm at the moment."
With a reluctant leading man, the future of the franchise was looking troubled...
A new director at the helm
With things a little up in the air, the rumour mill went into overdrive.
One such story which turned out not to be true (praise the lord!) was the one that suggested Russell Brand would be playing Jack Sparrow's pesky younger brother Jonathan.
You can see why the tabloids would have fun suggesting the scruffily-barneted dandy as a sibling to Sparrow, but it never came to pass.
Stories about Tim Burton and Sacha Baron Cohen boarding the franchise were similarly debunked.
Early in 2009, director Gore Verbinski stood down, opting to focus on the now-defunct BioShock movie, and animation Rango (which will feature Depp's vocal talents).
He left with the statement: "I had a fantastic time bringing Pirates to life, and I am eternally grateful to Jerry, Johnny and the rest of the creative and production team... I'm looking forward to all of us crossing paths again in the future."
There's obviously no hidden subtext here, as Verbinski has recently been confirmed as the director of Bruckheimer and Disney's next big project: The Lone Ranger , starring one Johnny Depp as Tonto.
Looks like he'll be reuniting with the old team sooner than expected.
Verbinski's predecessor was announced a few months later.
Rob Marshall, who comes from a stage musical background, is best known for directing Nine , Memoirs of a Geisha , and the Oscar-winning Chicago .
Marshall seemed like an unlikely choice, but he has experience wrangling big starry casts, he's no stranger to spectacle, and he'll no doubt feel at home amidst the flamboyant characters and costumes.
Being picked by Bruckheimer and Depp must have been a confidence boost.
The incumbent director told Coming Soon "I was so surprised they called me... Jerry called me, but Johnny was interested in working with me. It's a wonderful thing when something like that happens..."
The franchise has a captain again...
Finding a source
When Pirates of the Caribbean 4 got its all-important subtitle, it sparked a great deal of interest.
Unlike previous franchise entries, On Stranger Tides points to material that already exists, namely Tim Powers' 1988 novel of the same name. Risky idea basing the fourth entry in a series on unrelated material?
Well, there are a some coincidences. For example, the book features a pirate called Jack, and the plot fits in well with Sparrow's search for the Fountain of Youth, which was hinted at towards the end of the last film.
There's also the character of Blackbeard, who's set to make an intriguing addition to the series' rogues' gallery.
Franchise writing stalwarts Ted Elliot and Terry Rossio are still on script duties, but it might help if they're working to a pre-set story.
One of the biggest failings of the previous Pirates sequels was their overly convoluted and needlessly complicated plots.
Due to the hectic back-to-back shooting schedules of Dead Man's Chest and At World's End , Elliot and Rossio were forced to write on the hoof, as the film went into production without a finished script.
Working from Powers' novel will hopefully help the writers to keep the film on track.
Powers' novel has also been cited as an influence on Monkey Island creator Ron Gilbert, who was also inspired by the original Pirates of the Caribbean theme park ride, so they obviously share some sort of DNA.
Could be the ideal basis for some high-seas fun...
Jack Sparrow may be returning, but some familiar faces won't be.
Elizabeth and Will, played by Keira Knightley and Orlando Bloom, aren't coming back.
It's hard to imagine many fans being too upset by their absence.
The pair made an interesting foil to Sparrow in the first movie, but the sequels didn't seem to know what to do with them.
The couple also got some post-credits closure at the end of the the third film, so it was no surprise to hear that they wouldn't be returning.
Knightley was quite vocal about her decision to leave the franchise behind, telling Moviefone: "It was a completely fantastic experience, and it was an amazingly large portion of my life, but I don't think I need to go there again... I think that it's done. But I'm very excited to see the next one."
Knightley's gathered quite a diverse number of projects post- Pirates ( Never Let Me Go , Last Night and Cronenberg's A Dangerous Method are all set to be released in the UK next year), so it seems she's made the right decision.
Orlando Bloom wont be returning to the fray either.
After making mammoth commitments to the Lord of the Rings trilogy and then Pirates , the actor apparently chose to spend more time with his model wife Miranda Kerr (who's expecting the couple's first baby).
Bloom has filmed roles in a handful of smaller-scale projects ( New York, I Love You , Sympathy for Delicious and Main Street ), but he's set to buckle his swash again in Paul WS Anderson's 3D retelling of The Three Musketeers .
While Bloom and Knightley are out, there will be some familiar faces for Depp on set...
Geoffrey Rush's Captain Barbossa is back.
It's hardly surprising considering the third movie saw him on the hunt for the Fountain of Youth, and he's obviously a longstanding rival of Sparrow's.
As the shots of Barbossa in costume seem to confirm, he is now a privateer for the King's Navy, though he's still searching for the elusive Fountain.
After he was officially attached to the project, Rush told MTV that the writers were going to "take it off into a new direction, so that it's fresh and hopefully really interesting for an audience, that they're not going to just sausage-machine out something else, which would not be so good."
Legendary Rolling Stones guitarist Keith Richards is set to reappear as Captain Teague (AKA Jack Sparrow's dad), with a prominent appearance in the trailer quashing any rumours that he had been left on the cutting room floor this time around.
Kevin McNally is also reprising his role as series regular Joshamee Gibbs, a regular member of Jack Sparrow's crew.
It does perhaps suggest that, despite the change in director, and the jettisoning of Will and Elizabeth, the new movie isn't going to stray as far from the trusted formula as some expected.
It had been rumoured that the lack of Orlando and Keira would mean more screentime for Sparrow, but Depp seems to have nixed that.
He told an Alice In Wonderland press conference: "There's no Keira or Orlando in there. I don't think we'd ever throw too much Jack Sparrow in there. There will just be a little bit of everybody."
So, who else is coming aboard?
Ian McShane's casting as Blackbeard was one of Pirates 4 's biggest coups.
The erstwhile Lovejoy star enjoyed something of a career revival with his role as Al Swearengen in TV's Deadwood .
He has since purred his way through a number of support roles in everything from Hot Rod to 44 Inch Chest , by way of Kung Fu Panda , but this'll be his biggest movie outing to date.
If he can bring an iota of the menace, gravitas, and depth that he brought to Swearengen, then Pirates fans could be in for a treat.
The uber-villains have been one of the franchise's strongest weapons, and McShane could fit right in with Bill Nighy and Geoffrey Rush.
It's also surprising that infamous marauder Blackbeard hasn't been utilised by the series until now.
Penelope Cruz was another tantalising piece of casting for the franchise.
The Spanish actress (who Marshall got a scintillating turn from in Nine ) plays Angelica, daughter of Blackbeard and love interest of Sparrow: perhaps this movie will have a tighter plot than it forebears...
The trailer suggests she's bringing the feist that Keira never seemed to summon in her Pirates outings, and she's as lively in the verbal sparring as she is in the swordplay.
Ever the professional, Cruz isn't one to let a little issue like pregnancy get in the way of a role.
Apparently the costume team have been coming up with a number of creative solutions for covering the bump, and her sister Monica has even stood in for her for long shots.
This Is England actor Stephen Graham continues his ascent through the Hollywood ranks by nabbing the role of Scrum, Richard 'Uncle Monty' Griffiths is playing King George II, and Judi Dench (another of Marshall's Nine alumni) is set to appear in an unspecified cameo.
And they're not the only franchise newbies...
"There be dangers along the way..."
The Pirates franchise is well known for its larger-than life supernatural enemies.
Keen to raise the stakes, the franchise contains two new mythical species.
First up there's mermaids. We only get a brief glimpse of them in the trailer, but we know that they're going to be easy on the eye.
Model Gemma Ward is playing queen mermaid Tamara, and actress-model Astrid Berges-Frisbey will play Syrena, who appears to fall in love with missionary Philip, played by Sam Claflin (will they be this movie's Keira and Orlando?)
The trailer also reveals some zombie hordes for Sparrow and his crew to take on.
They don't look like the Romero breed of baddies, more like particularly bad-ass pirates, or something out of a Sinbad adventure, which is no bad thing.
So, the mermaids seem to be bringing a bit of mystique, while the zombies are providing the brawny threat.
Looks like Bruckheimer and co have all bases covered, but will they end up with too much on their plates?
Jack's going jetset
Unlike the original trilogy, which was largely shot on location, On Stranger Tides has used Hawaii as a Caribbean stand-in (we can't imagine the cast and crew were too devastated by that), as well as taking a jaunt to these shores for some filming in Greenwich Docks and Pinewood Studios.
Depp made headlines around the world when he visited a local school while shooting in Greenwich.
Making the planet's female population swoon even more heartily, Depp responded to a school kid's letter asking him to come in to help stage a mutiny against the teachers.
Arriving unannounced in full Jack Sparrow costume, he turned up for an impromptu assembly.
Depp's generosity and obvious passion for the character seemed to charm even the most Pirates -cynical people out there.
And the film looks to be making effective use of its locations.
The exotic locales are visually in keeping with earlier entries in the franchise, and the London-set action has a suitably convincing period sheen.
It should be refreshing to see Sparrow outside of the holiday brochure locales.
The budget is making room for 3D
In a totally unsurprising move, On Stranger Tides will be shot in 3D, using RED digital cameras.
It'll also arrive on super-sized IMAX screens, and, y'know, regular ones.
Barely a blockbuster is released this days without 3D being at least a consideration, so it wasn't a shock to learn that Jack Sparrow would be returning in multiple dimensions.
Thankfully the production crew have invested in 3D camera technology, rather than simply attempting to convert regular footage in the post-production stage.
The visual effects will apparently be 'post-converted' to save a little cash though.
In this tough economic climate, Disney has scaled back the budget of this latest adventure.
Bruckheimer commented on the situation to Moviefone: "We all want to make pictures for less. I've never made a picture that the studio didn't say they wanted for less. That goes on all the time."
"Whenever we come up with a budget they always want to cut it way back, so that's normal."
Bruckheimer also assured the LA Times that the audience won't miss the budget, which is down $100m from At World's End's $300m.
The trailer doesn't exactly smack of budget cuts though.
The not-cheap cast don't seem to be short of set-pieces, and perhaps the limited budget will help guard against the throwing everything at the screen mentality of Parts II and III .
This could just be the beginning...
Despite the uncertainty that marked the beginning of On Stranger Tides ' production, don't count out further installments in the franchise.
Disney are already optimistic, with Head of Production Oren Aviv stating that this installment will "hopefully be the first of another trilogy."
Depp has always worn his affection for the character on his sleeve, claiming: "I wanted to to play Captain Jack again because he's so much fun to play and there's so much more to explore... I'm there. Why not?"
Recently there's been talk of filming Pirates 5 & 6 back to back.
Expect to hear news of future franchise installments shortly after On Stranger Tides ' box office tally is counted.
Given the buzz that's surrounding this next entry, we can't imagine that audiences are going to be bored of Jack Sparrow anytime soon...