Ezio's two adventures after Assassin's Creed 2 made us believe that after Assassin's Creed 3 we'd be seeing much more of new assassin Connor and his American Revolution setting.
Surprisingly one year on, the series will move onto a brand new instalment, hero and era, and another leap forward in scale and exploration.
While previous games explored the Crusades and the American Revolution, this takes you to the golden age of piracy, and with it dozens of locations brand new to the franchise.
Your ship is a 'second main character'
It wouldn't be a pirate game without a ship, and the one you command – the Jackdaw - is described as Assassin's Creed 4: Black Flag's second main character. It's key to exploration and setting the world, and without it, nothing would happen.
It can be evolved through customisation and upgrades, letting the player choose between an agile vessel for exploration, or to arm it to the teeth for engaging enemies. Crew members can also be recruited throughout the game, or lost in the course of battle and through natural events, such as storms.
Ubisoft were keen to stress that exploration was seamless. You'll be able to leap from your ship into the water and onto land with no load times.
With the Spyglass at hand, you can survey the horizon distractions thanks to on-screen gauges hinting at possible spoils and secrets. See a distant cargo ship or a distant cove? You're able to travel over and tackle it without interruptions. It's said to be the first true open-world naval game.
While Assassin's Creed 3 didn't invite players to explore the wilderness as much as some might have liked, there's an inciting whiff of Far Cry 3 here, especially since it shares a similar tropical, bounty-laden paradise.
That said, while the world is open to exploration, it's suggested that early in the game powerful vessels will hinder your progress to faraway destinations, requiring a gameplay loop of exploration, plundering, upgrading and defeating enemies before you can see more, and to ensure you're ready for what's in store.
The biggest Assassin's Creed world yet
Assassin's Creed 4: Black Flag is not only the biggest game world the franchise has presented, but also the most diverse, with over 50 unique locations to visit.
Cities obviously return, and offer three different flavours; Havana is the most European in architecture and population, while Kingston is dominated by British forces. Nassau, meanwhile, is described as a pirate haven.
You'll see much more if you take to the waves. Fishing villages are potted around archipelagoes, which are perfect for finding side missions or repairing your ship. Plantations can be plundered, showing that pirates pillaged from land-based targets and not just ships.
Hidden coves are a hive for smugglers (and loot), while coconut islands offer sun-kissed beaches and a prime opportunity to recruit more crew members.
Forts, meanwhile, are the perfect demonstration of that seamless exploration discussed earlier, allowing players to go from their ship to water and land as part of their attack.
Jungles offer an interesting counter-point to the forests we saw in Assassin's Creed 3. While Connor called the wilderness between Boston and New York home, new hero Edward Kenway isn't native to these parts.
It's said to be dense, claustrophobic and filled with dangerous animals. It also hides Mayan Ruins, adding extra mystery to this new landscape.
Finally, Assassin's Creed 4: Black Flag gives players the first ever opportunity to explore underwater. While you can't dive anywhere on the map, clues will hint at the location of shipwrecks under the waves, and battle sharks to retrieve the spoils within.
Dynamic naval combat builds on what we saw in Assassin's Creed 3
Naval combat make a popular debut in Connor's adventure, but it's now expanded to allow players to board other ships, whether as part of scripted missions or open-world encounters.
Grappling hooks will dynamically combine ships together, and from there you have a number of options in how to proceed. Do you free aim at the captain from a distance? Climb up the mast and free-run across, or use a rope to swing over and go toe-to-toe on the deck?
It's a 3D playground, but one you can't always take your time in; the longer your ship is engaged in another, the more heavy the losses to your crew, which are essential in operating your vessel.
Of course, not all ships can be easily boarded. There are five different ship archetypes that force you to adjust your combat approach. The charger, for example, will actively try and create distance between your ship and theirs in order to ram you.
Elsewhere, hand-to-hand combat has been tweaked to work in more confined spaces, such as ship decks, while Edward's four pistols mean that mid-range combat also gains more options.
It's also said to be more challenging, as lead content manager Carsten Myhill explains to Digital Spy: "[It's] more challenging in terms of the opponents, the window of opportunity and timing that you have with reacting to attacks by others.
"Generally across the board we're tuning and taking things up to a new level in terms of realisation and difficulty," he added.
Avoiding cliches and striving for historical accuracy
There's a worry that covering the pop-culture favourite pirates means that Assassin's Creed is betraying its historical heritage, but Ubisoft states that it's still just as accurate as other settings.
The publisher made painstakingly clear that it's avoiding the cliche-ridden approach that Hollywood has taken, and that things like sea monsters, skeletons and ghost ships won't make an appearance.
Cult figures such as the infamous Blackbeard will form a key part of the story, along with the likes of Ben Hornigold, Anne Bonny, Calico Jack and Charles Vane, pirates who clash over the direction of their new-found pirate republic.
Like previous games, hero Edward Kenway will have relationships and dealings with each character, and will be at the sidelines of some of the most famous events of the period, such as the massive wreck of the Spanish Armada and the marooning of Charles Vane.
Edward Kenway seems designed to counter Connor's flaws, giving him a personality and sense of charisma that fits the pirate lifestyle.
He will also seem to have to juggle his responsibilities as a ship captain as he stumbles into - and becomes involved in – the century's old war between Templars and Assassins that has been the backbone of the franchise to date.
You are the character in the new present-day world
With Desmond's character arc concluded at the end of Assassin's Creed 3, it gives Ubisoft an opportunity to explore new ways to tell the present-day battle between Assassins and Templars.
Since the timeline in the game world and the real world now marry up, players will "define who the character is", essentially playing themselves as they work for Abstergo and participating in the war by researching the era of Edward Kenway.
"All the previous Assassin's Creed games have been building up to this moment," explained Myhill.
"Now it's the perfect chance for us as Desmond's story comes to a natural conclusion, the real world and the Assassin's Creed world are now merged so we're not in real time.
"We're all in the Assassin's Creed universe right now. Assassin's Creed is real, is the way we like to look at it. So why not give the consumer, the player, the gamer the chance to be part of the Assassin's Creed universe themselves?
"Particulate in it, research Edward Kenway and be part of the universe and obviously discover the conspiracy and the war with the templars in a completely new way, not through the conduit of a third party like Desmond."
Details on what this actually means – in terms of how it plays and how it links in with Kenway's story in the 18th century – will come in the weeks and months ahead.
But if it's like previous Desmond unveilings – such as the surprise first-person exploration sections of 'Revelations' – we probably won't find out until much closer to release.
Multiplayer returns - but not on a ship
Finally, the fan-favourite multiplayer is confirmed to return in Assassin's Creed 4: Black Flag. While naval warfare is a key part of this fourth instalment, the advances seen in the campaign won't make their way over.
Multiplayer will remain land-based and will "definitely be pirate-themed and have that flavour of the time", explains Myhill.
"It's a shame, we really wanted to bring naval combat to the game. It's something that obviously everyone would love," he said, before adding that to bring naval "to a whole new level" the focus had to be on single-player only.
Assassin's Creed 4: Black Flag will be available on Xbox 360, PS3, PS4, Wii U and PC from November 1 in Europe and October 29 in North America.