The Terran Empire:  This is probably the most important land of Terra.  Terra's greatest power militarily and economically.  Home to the most legendary of adventurers.

The current Emperor, Stylus Steel, is considered by many to be a letdown to his family's legacy.  Stylus is a scholar and practical man.  He married early for political reasons and has produced no known offspring.  His first official act as Emperor was the recognition of Freeland as a seperate country.

The greatest military hero of the modern Empire is General Sigismund Odinson of the Bear Tribe.  He has been given the Axe of Might on semi-permanent loan by the Emperor.  Since the axe functions perfectly for him, including Beguilement function, some theorize that Sigismund is a better candidate for Emperorship than Stylus, positing that he may be one of Gladius's bastards.

The major export of the Empire is adventurers.  The Empire also has a lot of rich farmland producing much of the grain used in civilized lands.  There are also rich forests producing both wood and animal pelts.  Mining occurs in the hills and lesser mountains between the Empire and the Dwarven Mountains.

The capitol city of the Terran Empire is Terra Prima.  Terra Prima is a very big city where lawlessness is legal (within certain limits and subject to taxation and permit fees)  
[not strictly true:  in my early conception of Terra Prima, there was going to be perfectly legal and accepted above-ground thieves's and assassins's guilds ala Disc World.  That's getting a major rewrite];  
anyone or anything can be bought [still completely true:  there are few or no contraband laws, as such, slavery exists, and see the note below about finishing schools.];
bloodshed is a public sport (both in the Arena and at the Ace of Swords Tavern); halflings hang desperately onto their ethnic folkways (leading to Halflingtown a very foreign-feeling ethnic neighborhood); and dwarves lose theirs (leading to a very strong dwarven contingent in the Temple of Hephaestus and an almost unused Temple of Moradin).



Additional Notes:  The Tarot deck is known in the Terran Empire.  It has influenced culture in some interesting ways, particularly in Terra Prima where certain streets have Tarot-derived names, like Street of Swords, Street of Coins, Street of Cups, and Street of Staves.  It also leads to names of certain inns and taverns, like the Ace of Swords.

Finishing school is Terra Prima slang for a house of ill-repute.

Through some combination of actual technological progress and magic as technology progress, life in the big city is as comfortable as it is today in the real world.  That is to say, you might get your throat slit by unsavory characters, but food comes from a store, water arrives at your house, and some of the better sections of town have lighted streets at night.  Those doing the farming to make food arrive at the stores still live the backward and miserable life of medieval peasants, as do those living in the wild places far from the bastions of civilization.

Up until Stylus Steel took the throne, homosexuality was a crime.  His legalization of such practices is one more reason some of his subjects think he's a pansy.

Arcanum
Arcanum is the wizardly country.  It's bounded on all sides by The Terran Empire because it actually used to be part of the Empire.  An Emperor of The Iron Dynasty granted Arcanum its independence, with implications of a strong alliance between the two.

Arcanum is home to a number of lich crypts, mad wizards's towers, and similar likely adventure sites.  Of special note is the Temporal Palace or Spatial Palace, which may be two different places sharing the same space at different times.  It disappears and reappears at regular intervals.

The political and geographic center of Arcanum is The Great University.  The head of the University is head of state for Arcanum as a whole. (Under AD&D 2nd edition rules, every Wizard specialty class and kit has some sort of presence at the university, however minimal [even Rhabdomancers and Wu Jen from Dragon #229]).  The current Archchancellor of the University is Frater Gauge, a Geometer of great renown.  Never borrow money from him; he has a shelf full of souls forfeited; a half-dozen flesh golems made from extracted pounds of flesh; and a small army of Half-Ogres armed with big hammers and a keen interest in knee-caps.

Arcanum exports wizards, sages, magical knowledge, information, philosophies, magical items, new technology,  monsters (especially fusion-based aberrations along the lines of owl-bears), and gold plundered from lich crypts.  The Wizards import men of arms, raw materials (especially substances used for spell components, like amber), and individuals foolish enough to venture into lich crypts (a.k.a adventurers).

Religion is not much stressed in Arcanum.  Most wizards are eiter as agnostic as one can get in a world where clerical magic works, demons and celestials walk the land, and Ragnarock is impending; or else worship Hecate, Abraxas, Odin (imported from Barbarian lands), Thoth (an Elvish import), and/or Corellon Larethian (another Elvish import) regardless of alignment.

Being a crossroads of many cultures taking in the best and brightest intellects of all lands, Arcanum has almost always had somewhat looser social mores regarding sexuality than the Terran Empire.  Gay, lesbian, bisexual, or trans individuals are judged but their intellectual prowess and the might of the magics at their command, the same as anyone else.

The Law of Existence
This is an old custom of Arcanum.  Basically it states you can't kill a Necromancer for being a Necromancer, a Lich for being a Lich, a Vampire for being a Vampire, a Witch for being a Witch, a gay man for being gay, or similar.  A citizen is allowed to kill in self defense or kill those formally declared Renegade by the Archchancellor.  A citizen of Arcanum is defined as anyone holding at least one degree from an accredited magical university.  Non-citizens have no rights, but it is frowned on killing good support staff, especially if not immediately followed by animating the corpse as a zombie.

Barbarian Lands
The barbarians dwell to the north of the Terran Empire and to the south of Jotunheim.  They are divided into tribes, which are usually named after an animal.  Some tribes include: the Bear Tribe, which is the one that Terran Empire General Sigismund Odinson is from; the Wolf Tribe, rivals of the Bear Tribe; the Tribe of the Ram, sheepherders who wield claymores (the swords, not the mines); The Boar Tribe, where most of the half-orcs and half-ogres wandering the civilized lands originally hail from; and more that I haven't come up with yet.

Since each tribe is like a little country, it's hard to make sweeping generalizations, but here are some things likely held in common among a large number of tribes.

Most barbarians revere the Norse pantheon.  They place a major emphasis on living a warrior life.  The greatest fear of a barbarian is not death itself but death of old age rather than on the field of valor.  Right now, mercenary barbarians are a noticeable fraction of the Terran Empire's military might and this worries some Empire citizens.  

Most tribes do not develop a written language, but they do have a rich history passed down in sagas recited by skalds.  Every warrior dreams of having his conquests and death remembered as on of his tribe's sagas.

Most tribes are almost perpetually at war with the Jotuns to the north, the surrounding tribes and the Terran Empire.  It has long been a subject of much speculation that if the barbarians got their act together, they could be a major menace to either the Empire or the Jotuns or both.

Social equality of the sexes is actually much more advanced in barbarian lands than in the Empire, as a general rule.  Females can become warriors, own property, and lead tribes.  Even when leadership of a tribe is by a male, hereditary leaderships are traced matrilineally.  Everyone who is witness to the birth knows who somebody's mother was.  Fatherhood is often a little more ambiguous, especially among the barbarians.

While barbarians do marry, their customs are rather unusual by Empire standards.  Multiple simultaneous marriages are not uncommon, but they aren't of the a male may take as many wives as he can support variety that are known among the Empire nobles, rather, they could be expressed as: a person is married to another person as long as both of them say so and they can both marry as many other people as they wish.  To put it another way: polygamy is normal to the barbarians, but it's different from the sexist version that has existed historically on our Earth.  Besides the weird marriage customs, fornication and adultery are not uncommon and rarely considered that big a deal to most barbarians.  Homosexuality and bisexuality are rarely much frowned upon.

[It's worth noting that in terms of game mechanics not everyone from a tribe in the barbarian lands is of the barbarian character class and not everyone who belongs to the barbarian character class is from barbarian lands.  The percentage of barbarians in a barbarian tribe are noticeably higher, but only wizards are a rarity in barbarian lands.]

The Halfling Khanate
Halflings have a repressive feudal system not entirely unlike that of the Terran Empire.  At the top is the Khan.  He is head of state, chief executive, and the entire legislative body in one Halfling person and commander in chief of the military.  Below that is a warrior nobility called the samurai.  Next down are the townsmen, a middle class of merchants and craftsmen.  At the bottom are the serfs who raise crops.  Serfs technically have no rights when dealing with the samurai or Khan, including the  right to expect to be still living when the conversation ends.

The religion of the Halflings is animistic in nature.  They believe that everything is alive and has a spirit within it.  Spirits get fed by respect and worship and sacrifices.  There are also Gods who are spirits that are worshiped by so many people that they are no longer associated with a specific place but are kind of everywhere a particular activity is performed or a particular thing is found.

The halflings also have some of the scariest criminals in known Terra.  The Yakuza are said to be everywhere.  They supposedly know everything and can go anywhere.

While it is called the Halfling Khanate, there are relatively large populations of humans and korobokuru under their dominion.

Beast Lands
The Beast Lands are often thought of as a unit, even though they are really a group of small separate countries.  The main reason that causes others to lump them all together is that the inhabitants resemble humanoid versions of certain animals.  Beastlands races PCs know of at the start of the campaign are: Aarakocra, Alaghi, Bug Bears, Gnolls, Flinds, Kobolds (in my world, their rat-like traits are played up), Lizard Men, and Saurials.  With the exception of Gnolls and Flinds most of them are even open as PC races.

The Beast Lands continue further to the south than any currently know of and the following races may later be revealed: Rakasta, Lupin, Tortles, Minotaurs (stats will be as per the race from Dragon Lance, not the standard cursed humanoids from the Monstrous Manual), Cay Men, Gator Men, Pterra Men, Dracons, Giff, and Phanatons.

Religion varies widely.  Gnolls and Flinds are monotheistic Yenoghu fanatics.  Kobolds favor Kurtulmak and other Shadow Pantheon deities.  Alaghi and Aarakocra are primarily animists, tended to by Shamans.

Note: Anybody who sees the word Beast Lands and thinks of a Nuetral Good with Chaotic tendencies outer plane inhabited by Gaurdinals:  in my world that plane is still called The Happy Hunting Grounds, likewise the Nine Hells are the Nine Hells and not the Nine Hells of Baator.  Baatezu, Yugoloths, and Tanar'i are terms with no meaning in this world, especially yugoloths.  Evil outer-planar beings include: Demons, Devils, Daemons, Diakka, Demodands, and Hordelings.

More Ancient History
There was a time when all of Terra belonged to Dragons, Jotuns, Goblinoids, Beastmen, Dwarves, and Gnomes.  The Chromatic Dragons organized the Goblinoids and Evil Beastmen and Jotuns into the Dragon Empires that ruled Terra.  Scholars and historians claim this was over a hundred-thousand years ago, but this figure is much debated.  Then, Men and Elves came to Terra in sailing ships across the Great Eastern Sea.

The Elves claim that they arrived first and significantly disrupted the Dragon Empires.  Humans dispute this.

There were among the Humans arriving in Terra, two major peoples.  One came from the Northern Homelands and settled Northern Terra; these people worshiped the Aesir and Vanir and came to ally with the Dwarves and quarrel with the Jotuns.  The other people came from the Southern Homelands and settled Central Terra; these Men worshiped the Olympian Gods and befriended the Elves and destroyed the last remnants of the Dragon Empires.

The Goblinoids and Evil Beastmen scattered without the leadership of their Dragon Emperors.  Flint I of the Humans received the Artifacts of Rulership and married the Lady of Emeralds.
Approximately 80,000 years ago
Humans were the next race to invade.  The elves fought back hard, but had  an additional problem when a faction of their own race turned to worshiping dark powers including Lolth the Spider Queen.  Eventually the elves and humans came to an agreement to drive the newly christened Svartaelfs into the Dwarven Mountains.

The Good Aelfs and the humans agreed to split the known lands of Terra Nova.


Approximately 70,000 Years ago
A planar portal opened spilling the Horde of the Great Halfling Khan onto the broad fields claimed by The Terran Empire.  Another war breaks out and then a peace is brokered allowing the Halflings to settle.

Approximately 60,000 Years Ago
The First Dark Age begins.
It starts with the Terror of Yeenoghu's Chosen as the arrival of the Gnolls and flinds comes to be known.

Next comes the Northward march of the Goblinoid races from their distant southern home.

Next the Giants or Jotuns march south from their lands in the north.

Just when the situation seems to have hit bottom, the Hell Armies of Demons and Devils arrive from their home plane.

Finally the Gods war among themselves again.

Some of these situations are resolved fairly quickly, but their coming so quickly upon each other (some possibly within the same decade, and all definitely in the same century) causes a certain amount of technological and magical progress to be lost.  Not to mention the uncertainty of safety caused by having Goblinoids and Gnolls all in such close proximity to the civilized lands.

As things go downhill, The Ragnarok Prophecy is given.


Approximately 30,000 Years ago
The First Dark Age ends when the Gods bestow on the mortal races the Artifacts of Rulership.  The basic racially-based divisions of territory are established and The First Alliance is created.

Flint I of the Humans receives The Axe of Might, The Crown of Emperors, and Throne of Rulership (humans are big on useless symbols, but nothing says rulership like a big, heavy battle axe and the will to use it).

Hurn Ironhands, a dwarf, receives The Hammer of Might, Helm of The Dwarf Kings, and Mail of the Great Warchief (dwarves are a practical people and believe that headgear should be functional.  A dwarf king is as apt to sit on a bar stool as a throne, depending on what's available at the time.)

Jordan the Wheelright, a Halfling, receives The Daisho of Greatness, The Helm of the Khans, and Thunderhooves, a magic war pony (45,000 years in Known Terra have done strange things to the Halfling race.  Once they were a warrior Horde born to the saddle, now they are mostly farmers.  They still have the best cavalry of any nation, however.)

Shining Leaves, an elf, receives The Bow and Quiver of Excellence, Cloak of the Forest Born, and The Tome of Great Magics (Elves prize archery and magical ability.)

27,000 Years Ago
In reaction to the peace and stability the humans and demihumans now have, the Shadow Pantheon creates its own alliance of mortal champions and servitors (with the exception of Yeenoghu and Lucifer; both get lumped in with the Shadow Pantheon because of their common history in The Fall, however both have different aims than the rest of the Shadow Gods; Yeenoghu wants to kill all the other Gods; Lucifer wants to try and lead the world away from power and influence, including the power and influence of the Gods).

Hasan the Slayer, a human assassin, receives Old Man's Blade and The Black Armor (perfect tools for an assassin).

Martin Shadowen, a human shadow mage, receives The Shadow Book and Staff of The Shadow Wizards (his subsequent actions in the northern lands may account for some of the superstitious dread barbarians have of wizardly magic).

Kruk, an exceptional hob-goblin, received the Short Sword of Might, The Armor of Glory, and The War Drums of the Great War Chief (Hobgoblins respect functionality as much as dwarves do and war drums are the only way to get the lesser Goblinoids all marching in the same direction at once).

In secret, Yeenoghu delivers to his champion, an unnamed Flind, The Flind Bar of Might, The Cape of Yeenoghu's Chosen, and Bonechewer, a most exceptional Hyenadon (Because of Yeenoghu's madness, Gnolls and flinds are fanatical monotheists who hate all other sentient races).

Lucifer, Ssendam, and Ygorl secretly collaborate on The Cosmic Joke, a unique spell/ disease/ non-corporeal entity that can accomplish much with the right corporeal host, yet which is not under anyone's control, particularly not the entities that created it; They believe that to be part of the punchline.

25,00 Years Ago
The Age of the Great Artificers starts.
Martin the Conjurer creates the Ring of Servants.
Hermes Spacebender creates the Temporal Palace.
After he comes into possession of the Ring of Servants, The Golem Maker creates the staff of servants as a companion piece.

20,000 Years Ago
Second Dark Age Begins.
Shadowen the Lich-King's undead legions march on the Terran Empire.

17,000 Years Ago
Shadowen's armies are driven off by General Iron who has displaced the Flint Emperor and seized the artifacts of rulership.  
The Shadow Book and Staff of the Shadow Wizards are lost but almost definitely not destroyed.
Second Dark Age Ends.

15,000 Years Ago
Arcanum Secession:
Although it meant a loss of Empire lands and native magical talent, the Iron Emperor allowed it because the lands the wizards wanted included a number of mad wizard's keeps, lich lord's crypts and other undesirable properties would now be Somebody Else's Problem

10,000 Years Ago
The Second Gnoll War

8,000 Years Ago
The Land of The Northern Barbarians is officially recognized as a political entity separate form the Empire.  The Iron Emperor recognizes it as a way to make the Jotuns Somebody Else's Problem.

7,000 Years Ago
Draconic Resurgence/ Third Dark Age.
Lasting after-effects include: Therion, Scaleytown, Scaly Common, and the bloodline that leads to Martin Dragonblood.

5,000 Years Ago
Third Dark Age ends.

3,000 Years Ago
Age of Rust.
Iron Emperors become ruthless, decadent, mad, or combinations thereof.  Empire starts losing territory, beginning with unofficial annexation of certain northern villages.

800 Years Ago
Castle Granite is lost to Goblinoids.

150 Years Ago
The Sorceress appears and creates a forest for herself in the southern portion of the Empire.
  
100 Years Ago
Manus Iron begins trying to halt rust with what might be called an Age of Polish.  Campaigns extensively against Barbarians, Goblinoids, and Beastlanders.

Appendix: Dwarves: A Race That is Eternal
As far as the Dwarves are concerned they have always ruled the world and their empire has never failed because their world is The Dwarven Mountains.  They have some challenges, yes; mainly fighting the Svartaelfs and their own dark cousins and the illithid and others who contest their underground realms, but they are still where they were meant to be, in the mountains.


Appendix 2: So What about Gnomes?
Dwarves of both the normal and Duergar variety and Gnomes of regular and Svirfneblin types are probably the only races native to Known Terra.  The gnomes have always just sort of been there.  They haven't really had the urge to establish a kingdom of their own.  They are perfectly content living under the rule of dwarves, humans, halflings, or elves.