There's a few hundred millennia to cover, but our guide will make sense of Titans, World-souls, and banshee queens.
The Battle for Azeroth is set to kick off this week, with World of Warcraft’s latest expansion once again putting a focus on the bloody conflict between the Alliance and the Horde. But just what are we fighting for? How did we all get here? Why is there a moon-sized sword sticking out of the desert? The lore of the Warcraft universe is pretty expansive and convoluted, so here’s the crib sheet version with a helpful TL;DR (Too long; didn't read) for each section in case you really just want the highlights.
A Really Long Time Ago - The Titans Have A Disagreement
Long, long, long before the first life on Azeroth, there were super powerful cosmic beings called Titans. They roamed around ordering the universe, filling planets with servants made of stone and metal. Many of Warcraft’s races are descendants of these Titanforged, including dwarves and humans. New Titans, we learned recently, are born from World-souls, of which Azeroth is one. Yeah, we’re basically living on a giant Titan egg. That’s going to become important later.
Now there’s this one Titan called Sargeras who didn’t really see eye-to-glowing-eye with the rest of the Titan Pantheon. He discovered these other crazy space beings called Void Lords who were sending their Lovecraftian servants, known to Azerothians as the Old Gods, to latch onto World-souls like parasites in the hope that they would give birth to a Dark Titan. That would be really bad, but the other Titans didn’t much like Sargeras’ proposed solution… which was to destroy all the World-souls and, consequently, all life in the universe so there would be nothing for the Void Lords to corrupt. You can't corrupt living creatures if there are none, after all. So Sarge went off to do his own thing, creating the demonic army known as the Burning Legion.
TL;DR: The Titans hatch out of planets. But the Void Lords want to make an evil Titan, which would be bad. Sargeras thinks the best way to prevent this is to get a bunch of demons together and destroy all the planets, but everyone else thinks this is pretty much whack.
A Long Time Ago - Azeroth Has A Bad Case of Old Gods
Eventually, the Titans showed up on Azeroth… only to find that the Void Lords had already sent four Old Gods there and they were having a grand old time ruling the whimsically-named Black Empire. With the help of their Titanforged servants, the Titans defeated the Old Gods and the father of the Titans, Aman’Thul, grabbed the Old God Y’Shaarj and straight ripped him a new one. As it turns out, this was a very bad idea, causing the continent of Pandaria (where those sweet panda monks come from) to be plagued by echoes of Y’Shaarj called the Sha that feed on negative emotions and start all kinds of trouble to this day. Until they could figure out a way to actually kill an Old God without that happening again, the Titans decided to imprison them within Azeroth and call it good for now.
Over time, though, the Old Gods’ influence was felt as they slept. Among other things, they afflicted the Titanforged with the Curse of Flesh, which is why humans are made of meat and not iron (as the Titans originally intended) in the present day. Things were mostly cool for a while, though. Some trolls drank out of a magic well, turned into immortal Night Elves, and founded the next great empire.
TL;DR: The Old Gods ruled Azeroth for a while, until the Titans decided to put a stop to that. Turns out killing them has really unfortunate side-effects though, so they got put in Old God Jail deep below the ground instead. Oh, and the elves are a big deal now.
10,000 Years Ago - The War of the Ancients
At the height of the Night Elf empire, the Burning Legion came across Azeroth and realized it had a World-soul, so obviously they felt they needed to burn it down. One of Sargeras’ top demon generals, Archimonde, realized he could use the Well of Eternity, which had created the Night Elves, as an energy source to open a portal big enough for all of his demon buds to come through and attack. With the help of the powerful Dragon Aspects (except Deathwing who went crazy because of the slumbering Old Gods), several Night Elf heroes—including brothers Malfurion and Illidan Stormrage, and their mutual love interest, the moon priestess Tyrande Whisperwind—managed to defeat the Legion and save the world.
Kinda.
In the midst of all of this, the Well of Eternity went nuclear and sundered what was at that time a single supercontinent into the landmasses of Azeroth as we know them today. The Night Elf ruler, Queen Azshara (who had been collaborating with the Legion because she was corrupt and power-hungry as all get out) fell into the ocean with some of her followers and they got turned into serpentine naga. Word is she’s going to be a pretty big deal in Battle for Azeroth.
TL;DR: After the first game of the playoffs, it’s Azeroth: 1, Legion: 0. Except a really powerful magic well blew up and now Azeroth has lots of continents and a really angry snake lady who lives underwater and still wants revenge.
Around 33 Years Ago - Orcs and Humans
Jumping ahead a few millennia, the events of the original WarCraft RTS and WarCraft II: Tides of Darkness cover the collision of Azeroth and orc homeworld of Draenor. On the latter, Sargeras corrupted the orcish race with fel energy in an attempt to use them as shock troops for his second invasion of Azeroth. With the help of the corrupted human Guardian, Medivh—Azeroth's version of a magical Captain America—he opened the Dark Portal to the orc homeworld of Draenor and set his orcish army on a path of destruction, opposed by the humans, dwarves, gnomes, and high elves (distant cousins of the Night Elves who evolved to be less tall and less purple) of Azeroth’s Eastern Kingdoms.
After two brutal wars, a group of Azerothian heroes traveled to Draenor to stop the invasion at the source. But the orc Ner’zhul began throwing open many portals to other worlds, which destabilized the whole planet and blew it up. What was left of it became Outland, the setting for World of Warcraft: The Burning Crusade. As for Ner’zhul, his spirit was plucked out of space by Kil’Jaeden, one of the other main generals of the Burning Legion, put into a crown, and given psychic powers to control the undead—the first Lich King.
TL;DR: Sargeras decides to corrupt the orcs and use them to destroy Azeroth. It doesn’t go so well and the orc homeworld gets blown up, leaving many of them stranded on Azeroth. One of their former leaders becomes king of zombies.
Around 23 Years Ago - The Legion is Back
After the failure of the orcs, Sargeras uses Ner’zhul to raise an army of the dead to attack Lordaeron, the most powerful human kingdom. Jumping in to defend it are super-paladin Uther the Lightbringer, the crown prince Arthas Menethil, and a talented mage, Jaina Proudmoore, daughter of the Admiral of Kul’Tiras—a naval power which will form half of the main setting in Battle for Azeroth. Things are not all as they seem, though, as Arthas is being psychically seduced by Ner’zhul to come to Northrend and become the physical vessel for the Lich King. Arthas claims the cursed sword Frostmourne, goes crazy, and starts killing everyone.
Jaina runs away to find allies on the forgotten Night Elf home continent of Kalimdor. Arthas kills his father, takes the throne, and proceeds to really do a number on Lordaeron and the high elven kingdom of Quel’Thalas. His ruin of the elves is opposed by Ranger-General Sylvanas Windrunner, whom he kills and raises as the Banshee Queen in his service. She is very, very unhappy about this and will ultimately break free to found her own faction of vengeful, free-willed undead, The Forsaken.
TL;DR: Sargeras decides to try zombies this time. The Prince of Lordaeron is seduced by the Lich King with a magic sword, stabs his dad, stabs the general of the elf army, and brings the latter back as a badass zombie archer queen.