Before I begin, I would like to state this is all in flux still. A lot of things may need tweaking or removing all together. Also, the time frames are rough. They will be less well rounded later. That said, here is my current history.
Pre-history: The god-machine is put in the deep earth. This causes a mountain to grow above it to gigantic proportions. Both Giant Eagles and Griffins make the mountain home. The Labyrinth (Above and Below) is created by unknown forces. The Forgotten Armory is created, presumably by the same unknown forces as the Labyrinths.
2500 years ago: Mord Mar founded by dwarves, led by Bradel Greybeard. The endeavor is funded by mithral, gold, silver and platinum mined while excavating.
2400 years ago: Var Nae opens for outside races to trade with dwarves.
2250 years ago: Mord Mar's main city and crypts are completed.
2225 years ago: The Feeding Caves are completed. (after the fall became known as Feeding Pits).
2200 years ago: The goblins of Mord Mar stage a revolt and gain freedom from dwarves.
2199 years ago: Goblins find the Humanoid Holds. The goblins that survive here grow to become hobgoblins and bugbears.
2195 years ago: Bradel dies, succeeded to the throne by his daughter Cense Greybeard.
2175 years ago: Cense orders work begun on the "Great Bazaar Below."
2170 years ago: Cense dies in her sleep. Her son Tyran Greybeard ascends to the throne.
2150 years ago: The "Great Bazaar Below" opens for any race from below the surface to trade. Tyran orders the building of sewers, waterworks and tunnels to maintain them.
2145 years ago: Drow declare war on Mord Mar.
2100 years ago: The Drow Wars end in a treaty. This treaty calls for the building of an arena to decide disputes between the races. The sewers are completed. Tyran retires from the throne. His son Ranid takes the throne.
2070 years ago: The Arena is completed. This marks the end of the Mord Mar dwarves delving deeper into the earth.
2000 years ago: The gods of Mord Mar reveal themselves, and replace the gods of the realm in the city. King Ranid dies in the arena to a Drow woman named Sh'al Nightstone. His son, Miter, takes the throne.
1950 years ago: a faction of secret "old god worshipers" begin digging the Cultworks. Many races take part in this, including the Drow, dwarves, deep gnomes, and others.
1945 years ago: Miter discovers a sect of heretics. Orders the jails built to house heretics and other unwanted. Miter (and Mord Mar) do not know about the Cultworks.
1940 years ago: Miter found assassinated in the sewers. His daughter, Jessa Greybeard becomes queen.
1925 years ago: Jessa's champion, Tanc Gembeard, defeats the Drow's Witch-Sorceress, Tan'eth Darkeye. Tanc and Jessa show mercy and spare Tan'eth's life.
1900 years ago: the Cultworks is completed.
1875 years ago: Queen Jessa is found dead. Tan'eth's body is also found in the queen's chambers. Trebor Greybeard ascends to the throne.
1870 years ago: The Grottoes and Caverns are discovered. Declared to be a natural area by King Trebor. The secret vaults of Grizzlegrim excavation begins.
1845 years ago: The Hellevator is first spotted in a grotto.
1830 years ago: Cella the Seer foretells the fall of Mord Mar.
1750 years ago: Trebor is killed in an ambush outside of the Great Bazaar Below. Trebor's son Fier Greybeard ascends to the throne. Orcs overrun the Bazaar. Work on the Teleportation System begins.
1745 years ago: Orcs pushed out of the Bazaar, and surrender to Mord Mar. The Goblin Mirror is taken as tribute from the surrendering orcs. It is put into a magical storage.
1700 years ago: A group of dwarves finds their way to the Lost Forge. All perish there.
1600 years ago: Fier Greybeard dies, his son, Boldin takes the throne.
1550 years ago: Boldin dies in the Arena. The victor Drow claims to be Sh'al Nightstone. Boldin's daughter, Necsa Greybeard takes the throne.
1450 years ago: The Great Wizard, Egg, builds his tower in Mord Mar.
1400 years ago: Necsa vacates the throne to lead a group of dwarves in founding a new city. Necsa's son, Gygan takes Mord Mar's throne.
1375 years ago: A huge red dragon, Crymsyn, attacks Mord Mar. Gygan kills Crymsyn with help from Egg's magics.
1300 years ago: Gygan retires. His son Eja, takes the throne.
1150 years ago: Eja dies. His son, Pence, takes the throne.
1145 years ago: Pence dies. His brother, Hone, takes the throne.
1000 years ago: Hone retires. Pressa Greybeard, Hone's daughter, takes the throne.
650 years ago: Pressa dies. Her son, Mikel, takes the throne.
500 years ago: Bear Yarl settles in peak of mountain. Teleportation System completed.
475 years ago: Mikel dies in the arena to Tel'ma Lightstopper, a male Drow. Tel'ma died to his wounds less than a minute after Mikel. King Ritham Greybeard ascends to the throne.
425 years ago: Bear Silva settles with Yarl.
400 years ago: Mord Mar struck with a 'ghastly plague.' King Roni ascends to the throne when King Ritham succumbs to the plague.
375 years ago: King Roni discovered to be a doppleganger. Two other houses attempted to wrest the throne from the Greybeard line, but Vor Greybeard was able to retain his birthright.
350 years ago: Mord Mar overrun by a 'demonic army, led by the Horsemen of the Apocalypse themselves.' Confirmed in the army are: Drow, deep dwarves, demons, orcs, goblins, bugbears, gnolls, hobgoblins, undead, and 3 dragons (red, black and blue). King Vor is killed in this attack. King Johan ascends to Var Nae's throne-in-exile.
325 years ago: Var Nae sends an army back into Mord Mar. This army is completely eradicated.
300 years ago: Mord Mar's Adventurer's Guild is formed.