What is now Marvel Comics was originally founded by Martin Goodman as Timely Comics. The first comic published by Timely, Marvel Comics #1, would later serve as the inspiration for the company's current name. Timely Comics starred several characters, many now forgotten, and a few that have stood the test of time, such as the Sub-Mariner, Captain America, Bucky, and the original Human Torch. Timely folded in 1950 and was picked up by Atlas Comics, which attempted to bring back some of the company's big super-hero names. Atlas, however, was not long for this world and closed in 1957.

In 1961 Marvel Comics launched with Fantastic Four #1, the brainchild of Stan Lee, marking the begning of the Marvel Universe. After Fantastic Four, the team at Marvel began rolling out various new titles featuring original characters such as Spider-Man and the X-Men, as well as characters revived from the old Timely days. This laid the foundation for what would become the Marvel Universe and marked the birth of a cultural icon.

While there is ongoing debate over industry wide standards for marking the start and end dates of these periods, the generally accepted markers for Marvel Comics are as follows:

The Golden Age marked the early development of the super-hero genre with characters such as Captain America, Namor The Sub-Mariner, and others.

The Silver Age saw an emphasis on character development and realism in characterization. In addition, Marvel strove to appeal to a more mature audience through the incorporation of more sophisticated content and themes as well as addressing myriad social issues. This period saw the premier of many of Marvel’s most recognized characters, such as Spider-Man, The Avengers, The X-Men, and many more.

Darker and grittier in both style and content, the Bronze Age approached topics that had previously been considered taboo, such as drug use and alcoholism. Building on the foundation established in the Silver Age, Marvel’s comics began to further explore socially and politically significant issues.

Continuing to the present day, the Modern Age of comics has been largely defined by a focus on industry trends and marketing gimmicks. This includes the rise of promotional events and crossovers, and the heavy saturation of titles for popular characters such as Spider-Man and the X-Men. The rise of direct-market sales and independent comic publishers also played an important role in the development of the modern comics industry.

The mainstream Marvel Universe employs a sliding time-scale that controls the passage of time within Earth-616 in relation to the passage of time in the real world. The result of this is that characters age little over the years while the world they inhabit adapts in real time to reflect our own. The purpose of this is to maintain the status quo of a character over time rather than having them grow old. This process has progressed over the years, with the first several years of Marvel continuity moving more or less in real time followed by increasing deceleration beginning around 1970.

A Story Arc is a story that spans more than one issue of a comic. A Crossover is a story arc that spans more than one issue through two or more titles. An Event is a broad story arc that is composed of multiple smaller arcs and crossovers, often with ramifications for the Marvel Universe as a whole.

Continuity is the practice of maintaining the details of a character’s history and characteristics over time. With multiple writers and artists working on a character or title through the years, carefully maintaining continuity is essential to ensuring the integrity of a character’s story. Retroactive Continuity (RetCon) is the practice of updating, adjusting, or altering the details of a character’s history for creative or practical reasons. This can range from the introduction of a never before mentioned sibling to the erasure of huge portions of a character’s history.

Over the years Marvel has used various alternative publishing brands, known as Imprints, designed to reach different niche and regional markets. Some examples include Curtis Magazines, Epic, Marvel Knights, and MAX, which were designed for mature audiences, Marvel UK, which was created to tap into the British market, or Tsunami, which was aimed at Manga readers. Whether or not a title is considered in continuity varies by title rather than Imprint.

Pioneered by Stan Lee and artists Jack Kirby and Steve Ditko, the Marvel Method is an alternative style of collaboration between the writer and artist in the creation of a comic book. Rather than write a panel-by-panel outline for the artist to follow, Lee would produce a one or two sentence synopsis of the story. The artist would then fill in all the details and action on his own, with Lee adding dialogue and narration to the finished art. This method gave the artist more creative control over the characters, and was an essential component in the development of Marvel Comics' identity at the time.

Earth-616 is the designation for the Mainstream Marvel Universe within the broader Multiverse. The concept of the Marvel Universe grew out of Stan Lee’s desire that his various characters inhabit the same fictional world. Within this world, which was intended to mirror our own, these heroes and villains would freely interact and the actions of one could have a significant impact on the lives and world of the others. Over time, through the maintenance of continuity and the input of hundreds of writers and artists, this mythology has grown to incorporate thousands of diverse characters and concepts.

Earth-616 is one of many universes that combine to make up the Marvel Multiverse. These various universes are comprised of alternate realities, dimensions, and time-lines that feature their own versions of many of the characters that are part of Earth-616. While some of these universes are standalone concepts, many of them interact to varying degrees with each other and Earth-616. As such, it is not unusual for a character from an alternate universe to appear in Earth-616, or for an Earth-616 character to spend time in an alternate universe. Nearly all of these universes will have a designation that is “Earth” followed by a set of numbers. The other Marvel Earths are:

Earth-0000 (Earth Prime): The Real World. Earth where the comics are written

Earth-9: Reality of Saturnyne (Mighty World of Marvel)

Earth-12: The Exiles' Mimic (Exiles)

Earth-15: Spider from Weapon X (Exiles)

Earth-26: Alternate Marvel Civil War (War Averted)

Earth-27: Magnus Lensheer (Child of Magneto & Rouge)

Earth-33: Non-Powered Fantastic Four (Fantastic Four)

Earth-36: Hazel Donovan (Startling Stories)

Earth-45: Dr. Doom Lobotomized (Fantastic Four)

Earth-65: Brother Brit-Man (Excalibur)

Earth-69 (AKA Earth-01000101): Reality of Tuatha De Turning. (Incredible Hulk)

Earth-98 (AKA Earth-1961): No sliding time scale from 1973 (Fantastic Four)

Earth-110: Reed Develops Global Technology (Fantastic Four)

Earth-127: Challenegers of Doom (Fantastic Four)

Earth-148: Kylun Adoptive Reality (Excalibur)

Earth-155: Superhero Civil War Averted (Dark Reign: Fantastic Four)

Earth-161: Alternate X-Men Development (X-Men Forever: Alpha)

Earth-172: Wolverine from Weapon X (Exiles)

Earth-181: Daredevil from Weapon X and Patch (Exiles)

Earth-231: Reed Kills Namore, Dr. Strange, Black Bolt, & Iron Man (Dark Reign: Fantastic Four)

Earth-238: Crooked World (Marvel Super-Heroes)

Earth-253: Protectorate destroyed by Qabiri (X-Man)

Earth-267: Kang sets of nuclear bomb in Washington (Avengers)

Earth-295: Age of Apocalypse (X-Men)

Earth-305: KaCaptain Angleterre (Might World of Marvel)

Earth-311: 1602

Earth-312: Slow Timeline (Exiles)

Earth-313: Lemurians (Knights of Pendragon)

Earth-355: Coal Tiger (Avengers)

Earth-371: Gambit from Weapon X (Avengers)

Earth-374: Procter, Sersi, and Ute (Avengers)

Earth-398: Queen's Vengence/Twilight Sword (Avengers)

Earth-412: Magic Carpet Rides (Wisdom)

Earth-460: Purple Man Initiates 1602

Earth-483: The Territory (Marvel Zombies)

Earth-520: Alternate Wolverine of Weapon X (Exiles)

Earth-522: Captain England (Daredevils)

Earth-555: New Universe (New Universal)

Earth-597: Nazi's won WWII (Excalibur)

Earth-617: Nightbane devestates Earth (Doc Samson)

Earth-653: Mesmero from Weapon X (Exiles)

Earth-665: Forbush Man (Not Brand Echh)

Earth-666: The Supernaturals

Earth-689: Scarlet Centurion convinces Avengers to capture super-heroes (Avengers)

Earth-691: Killraven (Marvel Super-Heroes)

Earth-700: Cassandra Locke (Marvel: Lost Generation)

Earth-712: Earth S / Squadron Supreme (Avengers)

Earth-714: Angel from Weapon X (Exiles)

Earth-715: Femizonia (Savage Tales)