I'll refine and add to it as time goes by.
Yes, some of it is contradictory. This is due to different nations using something like a bailey in different years.
Or having different inventors due to travel times or lack of communication with lands and nations they don't get along with.
Ages on Crestar
Age 1
construction of this pocket universe starts.
land, water, air, weather, some plants.
500 years go by.
Age 2 lasts 900 years
Somehow high elves are awakened. The Builder
notices and wipes them out. And yet, high elves
that came later remember these events.
The Builder might be an Other. Or a poor
quality Universe Overlord and Builder.
rest of the plants arrive.
Age 3 lasts 915 years
The Stone Age
Hill giants are awakened year 25.
Halflings are awakened year 33.
Dwarves and elves are awakened year 150.
Hill Giants and Halflings claim to be First Awakened.
Neither of them were first.
Orcs and goblins arrive year 375.
All animals are here by year 545.
By the year 650 all intelligent beings have
arrived on Crestar. Yet, there are Gates that open
from time to time. Evidently not planned by the Universe Overlord.
earthwork entrance to an earthen wall battlement invented.
Age 3 ends when the first Battle of Humanoids and Dwarves happens in the year 915.
Age 4 lasts 1,200 years
cool down starts at the beginning of this Age.
Most monsters that we would think of as Dinosaurs die off... maybe.
Orcs and ogres are almost wiped out by diseases after that war.
Elves and dwarves suffer as well. The elves blame the dwarves for
the diseases. Yet, they are not responsible. Possibly the
Overlord Builder made some mistakes.
Barbican: wooden pallisade guarding entrance to earthen fort.
Ditch: Even the early palisades had a ditch around them.
c Age 4 wood pallisade came into use, mostly around towns.
year 20 wooden pallisade guarding entrance to earthen fort
Age 5 lasts 500 years
Ice Age 1.
The Little Old Man in Gray is born.
Ertan helm first came about, probably this age, year and artisan unknown.
Arnan and Bartan helms probably this age as well.
Age 6 lasts 300 years
slight warm up.
Bronze Age starts.
Dwarf Home is begun in the year 420. They migrated here via Gate from Dwarf Hold.
Dwarf Hold is near the western edge of the Outer Ocean. One day the return Gate vanished.
Age 7 lasts 450 years
Tropical Age 1.
motte invented
Celtan helm, named after its maker Chago Celtran.
Age 8 last 2,000 years
Pleistocene starts. Cool down starts.
Age 8, 1,000 years Ice Age 2 starts.
Some civilizations move or die out.
Iron Age starts.
Various animals, many used for food, disappear.
Age 8, 1,900 years. Warm up starts.
Some civilizations revitalize, others move or vanish.
Tropical 2 starts.
Food animals return, some have a weird taste, some of the time.
Cool down starts.
Temperature zones/biomes clarify and become mostly final.
Animals present become normalized by biome. Large herds suddenly
shift location, sometimes by thousands of miles.
Some landmasses vanish, move, shrink, grow mountains and rivers.
Islands show up or vanish.
(Books shouldn't be dropped on keyboards... silly Universe Builder.)
In Age 9, various Peoples were asked what happened in Age 8 ? All reply that everyone
was too busy to write things down. They refuse to answer further.
Age 9 lasts 300 years
c. year 200 ballista by dwarves
Castle: A term applied to the fortified houses which developed in
year c. 300
Dartan helm, named by its maker John Shoethumper.
Motte-and-Bailey: A very early, but very effective, type of surface
gnome castle
Portcullis: First used in this age. Previously the gate was the only
way to block an entrance.
Age 10 lasts 900 years
battering ram
c. year 10 shell keep
A nose guard with wire cage, or nose guard, was added to some
Celtan helms in the Year 127 by armorer Yalno Tak-Nok.
c. year 500 Trebuchet used for the first time.
Steel becomes available.
c. year 500 Green Guild messengers started
Sharn-Nak Islands invaded via Gate: Year 500, Month 4, Outer Ocean
year 700 bailey summit of a motte added
c. year 840 A towered or crenellated manor house of wood
year 900, Month 7, day 20 the Undead Hordes attack. This is the end
of the 10th Age and the end of Licieria.
Age 11
Murder holes: A name given to holes in the vaulting of an
entrance passage, used to harass an enemy with missile fire.
wall towers early Age 11, square stone towers
Town walls of stone: no certain date for start, but common by Age 11
year 1 square stone keep
year 5 additional space added to a bailey for protection of the
garrison and owner. Baileys no longer used just for
combat or during a siege.
year 45 stone rectangular Barbican add-on to a castle
also stone wall, formerly a wood pallisade
year 75 stone round Barbican add-on to a castle
year 100 bailey protection for lord and garrison
year 100 Dtranyo Castle built, really a manor house of wood
year 110 hexagonal stone keep
year 127 inner and outer bailey, extensive size added to increase
protection
year 200 hexagonal stone wall towers
year 200 round stone keep
year 302 round stone wall towers
year 500 is the start of the campaign for player characters.
year 502 Holy Water/pottery head arrows invented