Ancient past-

A bored King Neptune travels back in time and creates a pocket universe filled with sea creatures that would evolve to become similar to mankind so he could one day rule over them, returning to his time afterwards.

250,000,000 years ago-

Squidward Tentacles arrives in this era with a time machine, teaching jellyfishing to a primitive star and sponge, only to be driven to his time machine by the primitive creatures when his clarinet playing enrages them.

23,000 BC-

The atlantean aliens arrive on earth, hauling their beloved over 900,000 year old bubble with them and forming a colony city in Neptune's underwater pocket dimension. They are allowed to stay by Neptune, and as a sign of respect name their city after Neptune's home, Atlantis.

7,985 BC (Minimum)-

Bubbles the Dolphin, a member of a species of time traveling dolphins dedicated to protecting the cosmos, begins watching over the solar system, maintaining order in it.

6,000 BC-

3 evolved sea creatures named Spongegar, Patar and Squog discover underwater fire, which Neptune had granted to them to make them more interesting, much to the chagrin of the other gods.

4,000 BC-

The atlanteans make first contact with the evolved sea creatures, sharing their knowledge with them.

Before 3,000 BC-

According to the Flying Dutchman, this is when he died. According to a Bikini Bottom legend, his corpse was used as a window display, and he haunts the 7 seas because he was never put to rest. However, this was merely a myth.

2,990 BC-

King Neptune creates a new body to use in his pocket dimension, which gradually grows to adulthood.

965 AD-

The evil Planktonamor, student of a great wizard, betrays his master and kills him and his students. However, the great wizard casts a final spell that would ensure Planktonamor's defeat, and be immortalized in the King's castle as a prophecy. Afterwards, Planktonamor creates a castle and uses a tamed dragon jellyfish to menace the citizens of Bikini Bottomshire.

1009 AD-

The last time a giant wave called the Big One rose for a thousand years.

1010 AD-

Prince Triton, the son of King Neptune, who had grown a fascination with mortals, is locked in a magical shrinking cage by his father until he learns to be a true god.

1013 AD-

Planktonamor discovers a drowning squirrel and grants her the ability to breathe underwater, and in exchange she becomes the guard of his castle, becoming feared throughout Bikini Bottomshire as the Dark Knight.

1015 AD-

Two young men from the future are summoned by the great wizard's final spell, and they manage to turn Planktonamor's dragon and the Dark Knight against him and defeat him. King Krabs is also taught how to make Krabby Patties. However, Planktonamor returns months later, his magic powers restored to full, and destroys King Krabs's castle. He then takes over Bikini Bottomshire, ruling with an iron fist.

1025 AD-

Spongicus Kane is recruited to the resistance against Planktonamor, and kills the Black Knight, Planktonamor's new enforcer. However, Dark Knight is killed in the process. Following this, Planktonamor begins a formal war against the resistance.

1030 AD-

The war ends with Planktonamor being killed, but Spongicus seemingly perishes with him, never to be seen again after a massive explosion. Their final battle is immortalized in legend.

1031 to 1203-

With Planktonamor dead, a massive power vacuum is left in the wake of the rebellion war. Because of this, over a hundred years of civil war occurs, with various factions vying for the title of ruler. Using Atlantean war weaponry, entire kingdoms are wiped off the map in these wars.

1204-

Disgusted by the destruction caused by their weapons, the atlanteans discontinue their weapon production, replace their tank's ammunition with ice cream in case they were stolen, and lock themselves away from the outside world. However, the two pieces of the amulet used to travel to and from their city still exist, but remain hidden for centuries.

1680-

Bikini Bottomshire's civil wars end with it being reunified and converted from a large city into a small town, being renamed "Bikini Gulch" and now having no real government. Despite this, the inhabitants enjoy their first taste of true peace in centuries.

1731-

The book of destiny, a book that allows its wielder to control space and time, is created by an evil titan sorcerer using dark magic. Pirates guided by Neptune stop him from conquering the universe with it, and their leader takes up permanent residence on Bikini Atoll to guard it, leaving behind traps, and the gods use their magic to grant him life after death.

1812-

Back in the sea, the great mollusk attack occurs, despite Patrick Revere's previous warnings about it. The mollusks are repelled, but there are still a few dozen casualties.

1882-

Ezekiel Plankton, AKA "Dead-eye Plankton", a descendant of Planktonamor, arrives in Bikini Gulch and takes over the town, renaming it Dead-Eye Gulch and forcing William Krabs, owner of the Krusty Kantina saloon and descendant of King Krabs, to give him his money in exchange for not being attacked. He also hires goons to kill any sheriff that tried to stop him.

1889-

Chimps from the surface begin searching for a banana peeler, and to find it they establish Treedome Enterprises Limited. The same year under the sea, Spongebuck Squarepants saves Bikini Gulch from Dead-eye Plankton, being immortalized afterwards in the form of a golden statue.

1890-

Spongebuck and his friends Pecos Patrick Star and Hopalong Tentacles star in a commercial for Spurskates, which is restored over a century later. The same year, a man named Amoeba establishes a new monarchy in an attempt to restore Bikini Gulch to its glory days.

1892-

William Krabs opens the Rusty Krab retirement home.

1902-

The first annual great snail race occurs. Lightning Larry Luciano is the winner.

1913-

King Amoeba dies of illness, and his daughter Tulsa takes control of the monarchy. However, she proves to be an immense tyrant, ruling over the newly renamed Bikini Bottom with an iron fist.

1915-

The people of Bikini Bottom launch a rebellion against Tulsa's tyranny, being led by a merman named Arion. This war would prove just as destructive as the Bikini Bottomshire rebellion war, resulting in hundreds of deaths. Notable participants in this civil war are Spongebuck and Pecos Patrick.

1918-

The Bikini bottomites launch an assault on Tulsa's castle, Spongebuck and Pecos Patrick sacrificing themselves to allow the rebels to break in. Tulsa is ultimately killed by the warrior Carl, and Arion takes the throne, renaming himself Neptune to secure his power. However, Tulsa's infant daughter survived and fled to the countryside.

1919-

Arion, now calling himself Neptune, begins annexing other oceanic cities, seeking to become king of the seas. However, this process would take many, many years.

1928-

A giant sea monster falls asleep in an abyss near Bikini Bottom, staying dormant for the next 79 years.

1929-

Ernie, later to be known as Mermaid Man, is born.

1934-

Tim, later known as Barnacle Boy, is born.

November 30th 1942-

Eugene Krabs and Sheldon Plankton are born, becoming almost instant friends from birth.

1949-

Mermaid Man and Barnacle Boy debut as underwater crime fighters, becoming celebrities overnight.

1950-

Krabs and Plankton are inspired to open a restaurant by the success of Stinky Burgers, and build a makeshift restaurant. Plankton also creates Karen to act as a security system, and the two begin dating as Krabs and Plankton work on their Plab Patty.

1951-

The Plab patty is completed, and when Krabs and Plankton discover that Stinky Burgers had been shut down by the health department, they give their Plab Patty to Old Man Jenkins, a family friend of Krabs's who had provided help for him and his mother. However, the Plab Patty ends up hospitalizing Old Man Jenkins. Because of this, Krabs and Plankton have a falling out, which leads to Krabs accidentally discovering the Krabby Patty formula. From then on, the two are mortal enemies.

1952-

Atomic bomb testing hits Bikini Bottom, and while Mermaid Man and Barnacle Boy are able to hold off most of the radiation, it hits a flownderfish and transforms him into the Atomic Flounder. These tests also shatter the barrier between Neptune's underwater pocket dimension and the suface.

1954-

Mermaid Man and Barnacle boy trap their enemy Man-Ray in tartar sauce, and keep him contained in their mermalair.

1959-

Plankton opens a mobile restaurant called the Chum Bucket, while Krabs becomes a pirate like his grandfather, buying a giant tartar sauce bin to use to feed his men, and not giving them any breaks.

1960-

Plankton goes to college, being bullied and stepped on by his fellow students for his entire time there.

1962-

Krabs and his pirate crew encounter the abominable snow mollusk, being eaten and having to wait for nature to take its course to escape.

1967-

Krabs's pirate ship is unable to find enough treasure to sustain itself, so he fires his crew and sells his ship. The same year, Arion launches an attack on the United republic of anchovia, the only independent sea nation left. The communist anchovies responded by attacking Arion's cities with their primitive fish mounts. And so, war was declared, with Krabs signing up as part of the navy.

April 18th, 1969-

Squillium Fancyson the third is born.

October 9th, 1970-

Squidward Tentacles is born.

1971-

The war ends after the leader of the anchovies is mysteriously assassinated, and the UROA is absorbed into Arion's kingdom, truly making him the king of the sea. After returning home, Krabs falls into a deep depression, isolating himself from the world and turning to the bottle to cope.

1972-

Krabs's mother convinces him to purchase the now bankrupt Rusty Krab and convert it into the restaurant he always wanted. Krabs does so, naming it the Krusty Krab after his old pirate ship. He transports the giant tartar sauce bin he had used as a pirate and in the navy into the restaurant. Thanks to the Krabby Patty, business takes off quickly, and the restaurant becomes very popular.

1973-

Krabs faces his first rival in the form of an elderly Stinky, who had created a new restaurant purely to spite Krabs, who he still saw as Rag Boy. However, Krabs routinely proves more successful.

1976-

An incident involving the destruction of a school in a superhero fight causes the bikini bottom Mayor to pass a super-being registration act, forcing superheroes to either give up their secret identities and become agents of the government, quit being superheroes, or become wanted fugitives. Mermaid Man and Barnacle Boy lead the anti-registration side, while a superhero called Metal Man leads the pro-registration side. This super-being civil war ultimately ends with Mermaid Man and Barnacle boy retiring, and Super-beings being outlawed entirely, with anyone who developed superpowers being executed. Thus the age of super-beings comes to an end.

November 17th, 1977-

The Squirrels Sandy and Randy Cheeks are born in Texas, United states.

1978-

Metal Man, now running for mayor, is assassinated by the father of one of the children killed in the school disaster. The same year, Stinky dies of a heart attack, leaving his restaurant to quietly shut down.

1979-

Plankton returns and makes his first attempt to steal the Krabby Patty secret formula, which fails. This formula would continue for the next several decades.

1980-

The first annual Fry Cook Games are held in the fast food coliseum. Krabs and Plankton compete against each other for years to come.

January 8th, 1984-

Larry the Lobster is born.

July 14th, 1986-

Spongebob Squarepants is born.

August 26th, 1986-

Patrick Star is born.

1987-

The quality of the Krabby Patty begins to decline, causing less and less customers to come to the Krusty Krab. Believing that he had lost his touch, Mr Krabs searches for a successor, and ultimately chooses a fry cook from the nearby Ukulele Bottom named Jim. Jim manages to bring people back in with his cooking skills, but Krabs still manages the Krusty Krab.

May 12th, 1990-

Mr Krabs discovers an unevolved whale that was killed by harpooners, and it's infant evolved daughter. Taking pity on the child, Krabs takes her and adopts her as his own, naming her Pearl.

1991-

Fresh out of college, Squidward Tentacles joins the Krusty Krew as a cashier as a stop gap until his clarinet career takes off. However, this never materializes.

1996-

The first half of the Atlantean amulet is found and placed in the Bikini Bottom museum.

1997-

Jim becomes fed up with Krabs's cheapness and quits the Krusty Krab. Afterwards, a fry cook Squidward later remembers as "Not Spongebob" is hired. However, his name was actually Jeff.

January 1999-

Sandy Cheeks is hired by Treedome enterprise Limited and for her first assignment is sent to the ocean to conduct experiments in her treedome.

April 16th, 1999-

Spongebob moves to Bikini Bottom, taking residence in a pineapple that had fallen from a cruise ship. This results in him being Squidward's neighbor.

April 20th, 1999-

Jeff dies in a boat accident, and with no fry cook, the Krusty Krab falls into disarray.

May 1st, 1999-

Spongebob joins the Krusty Krew after saving Squidward and Mr Krabs from a horde of ravenous anchovies.

May 2nd, 1999-

Spongebob meets Sandy and the two become fast friends.

February 14th, 1999-

Spongebob and Sandy try to give Patrick the best valentines gift ever. Jealous of all the gifts Spongebob received, Patrick goes on a brief rampage in the carnaval until he sees his gift, then calming down.

February 15, 1999-

The very first Annoy Squidward day.

September 28th, 2000-

The Fry Cook Games celebrate a 20 year milestone.

October 31st, 2000-

The Flying Dutchman's first interaction with Spongebob and friends.

December 30th, 2000-

Sandy introduces Christmas to the Bikini Bottomites.

2001-

The 21st annual Fry Cook Games occur, with Mr Krabs and Plankton being represented by Spongebob and Patrick.

2002-

Mr Krabs makes his 1,000,000th dollar.

2003-

The 102nd great snail race. Lightning Larry Luciano, who was still alive, lights the torch for the games. Rocky is the winner.

2004-

The 25th anniversary of Krabs and Plankton's rivalry.

2005-

The Mermaid man and Barnacle Boy movie is made.

2007-

Spongebob and Patrick accidentally discover the second half of the Atlantean Amulet, and they, Mr Krabs, Squidward and Sandy are taken to Atlantis. After shenanigans involving Plankton attempting to harness Atlantean weapons, the group leave.

April 17th, 2009-

Spongebob, Patrick, Squidward, Mr Krabs and Sandy become lost in a tidal wave. The Big One rises again, and is the reason they manage to return home.

November 17th, 2009-

The Krusty Krew celebrates the 117th anniversary of the Krusty Krab's building, while Plankton celebrates the 50th anniversary of the Chum Bucket's opening.

May 1st, 2010-

Spongebob discovers the Krusty Krab's now empty tartar sauce bin, and it is converted into a time capsule, set to be open in 50 years.

June 5th, 2010-

King Neptune celebrates his mortal body's 5,000th birthday. He is sad that his son Triton isn't there. Spongebob frees Triton, who proceeds to wreak havoc across Bikini Bottom, making his father proud. They return home afterwards.

July 15th, 2011-

Plankton holds a race throughout a winter wonderland with a million dollar prize as a plan to steal the formula. During this, Krabs comes face to face with the abominable snow mollusk once again. However, Plankton is ultimately foiled once again.

April 8th, 2012-

The Glove World theme park is shut down and replaced with Glove Universe.

July 8th, 2012-

Mermaid Man dies of liver failure.

2015-

The pirate Burgerbeard manages to get his hands on the book of destiny and uses it to steal the Krabby Patty formula, causing Bikini Bottom to devolve into chaos. Spongebob and Plankton, who were blamed for the theft, travel through time, and accidentally get Bubbles fired. However, the dolphin ultimately helps them and others who joined them breathe on land, and this allow the heroes to ultimately defeat Burger Beard and reclaim the formula.

2017-

While trying to hide from Spongebob and Patrick, Squidward accidentally locks himself in the Krusty Krab freezer, where he remains frozen for the next 2,000 years.

2019-

Barnacle Boy dies of normal pressure hydrocephalus.

March 7-14, 2033-

The Krusty Krab 2 is built, with Squidward being made manager since Krabs thought Spongebob was too immature. Plankton steals Arion's crown and frames Krabs for the crime. Spongebob and Patrick go to find the crown. Plankton finally manages to steal the Krabby Patty Formula, and uses it to sell chum buckets helmets to everyone, which he uses to control their minds. He also sends an assassin named Dennis to kill Spongebob and Patrick. Spongebob and Patrick manage to find the crown in Shell City, defeat Dennis, and ultimately defeat Plankton with the hard ballad Goofy Goober rock. Afterwards, Spongebob is made the manager of the Krusty Krab 2.

2060-

The Krusty Krab time capsule is opened.

2085-

Spongebob tells his grandson about the great train caper.

4017-

Squidward is unfrozen by a Spongetron robot, and discovers the future to be all chrome, and that there are 4,117 Spongetrons, one for each letter of the alphabet. He leaves the era with one of their time machines.

Unknown-

Squidward breaks the time machine, causing him to be sent to limbo. He's all alone, but ends up breaking down and admits that he misses Spongebob. Luckily, he manages to get back to the time machine and returns to 2017.