Old Ulthuan

Most elves come from "New Ulthuan". Mister Elf, where is old Utlhuan?
-inquisitive human child

As told my Ayemar, elven conjurer and storyteller
Unforunately child, Old Ulthuan is at the bottom of the sea...I see you want details. If you kids will sit quietly and listen, I am willing to happify y'all.

Defences

Old Uthuan was a horse shoe shaped nation with a mountain range going through the center like a spine. The inner nations were south of the mountains and the outer nations were north of the mountains. Most, but not all of Malekiths rebels were from the outer nations. Malekith himself was born in the northwest region and he was very sweet on his homeland, almost every invasion Malekith landed his forces in northwest Ulthuan and reclaimed his ancestral homeland, then he tried to push through the mountains. The mountains only had five easily navigable mountan passes and each one had a massive magically augmented fortresses that Malekith could never penetrate.
After four or five failed invasions, Malekith finally sailed around and entered the bottom of the horseshoe though this did not help in in the long run because his own capital was besieged while he was doing this.

Industry & Trade

Ulthuan was resource rich and underpopulated so they didn't need to trade with Humans or anyone else, but they did trade with the Empire of Man and other Humans because they wanted to maintain good political ties with them and be joint allies against Chaos. Without these trade ties, it is possible there wouldn't be any Elves or men alive today.

History

To hear Humans tell about the World that Was (or the Age of Magic as we Elves tend to call it), the all events were defined as a glorious battle between the Empire of Man and the Forces of Chaos, but it was more complicated than this. Men fought Chaos, certainly, but men fought men, men fought elves, Dwarves fought elves, Chaos fought Chaos. Greenskins fought everyone.
Elves fought elves. This was nearly constant in the Age of Magic. Long ago, the elves of Old Uthuan had a holy magic flame of the Assuyran, that a worthy leader could enter and exit unscathed while an unworthy leader was instantly utterly burnt to ash. This is how Ulthuan's leaders proved themselves. Until Malekith entered the flames, every elf either died instantly or emerged unscathed.
Malekith wanted to be emperor and he entered the flames. Rather than kill him out right, the flames grassed him. Malekith survived but emerged badly burned. His mother, the powerful witch of the Age of Magic crafted him magical armor that kept him alive fused to his skin to keep him alive. Elves lived a long time in those days but they were not immortal and did eventually succumb to old age. Malekith never seemed to age, but he was constantly in pain...not a life I would choose.
Malekith was pretty grum about being rejected by the flames, but he declared himself the rightful emperor anyway. He defected with a lot of followers. This split the elf race between the the elf race into the Ulthuani and Druchi or more commonly known today, High Elves and Dark Elves. They were outnumbered and had to flee Uthuan to regroup, eventually settling in a land called Nagaroth.
The Dark Elves rebuilt their numbers and had a slave based economy primarily enslaving humans. The High Elves took heavier losses fighting Chaos, Skaven, and various humans than the Dark Elves did. Malekith was able to trick the High Elves and dwarves into fighting a long war called the War of the Beard. When all the dust settled, where once Malekith and his rebels were a small miniority of the elf population, now the Dark Elves and High Elves were roughly on par with each other numbers wise.
Malekith tried to invade Ulthuan many many times. He always failed and had to flee back to Naggaroth but this inflicted great damage on the High Elves. In between these invasions, Malekith and his cronies went on slaving raids or treasure raids against the Empire of Men and other foreign powers.
Malekith tried to form a temporary alliance with the Warriors of the Chaos, and this blew up in his face. The Dark Elves took a lot of losses fighting the Empire of Man and the ancient Rangos alongside the Warriors of the Chaos and then the alliance broke down and the Dark Elves and Warriors of Chaos turned on each other.
Ulthuan caught wind of the Dark Elves loss of manpower and for the first time in their history, launched a major invasion against Naggoroth. Malekith opted to defend his land with a counterattack so both elf powers now had a substantial beach head on the others territories.
Who won? That depends on what you count as "winning". Both the Ulthuani and the Druichi claim they won and the other side lost.
The Druichi lost more people than the Ulthuani did but Ulthuan lost more land. They lost all of their land in fact. Ulthuan was not a normal island. It was magically floating on the sea with the whole island serving as a padlock on the jailhouse door of the Chaos Realm. Malekith as a last act of spite interfered with the magical balance and this led to the manifestation of the Demon Lord Slaanesh and eventually caused Ulthuan to sink into the sea. If there is one thing to say about Malekith, he spent his long life stewing in his own juices, and it's not at all surprising that his death not by the hand's of an enemy but by his own actions.
Fortunately, Ulthuan sank very slowly so most of the Ulthuani were able to escape and they escaped to Naggoroth, what we now call New Ulthuan. All of the slaves were set free and most of them were resettled in Hammerica. Unfortuantely, a lot of the slaves were given a dirt nap by spiteful masters in the twilight days of Naggoroth. They also managed to save a lot of treasures from Old Uthuan unfortunately most of the magic items have lost their old power and are little more than beautifully crafted paper weights.
A lot of the Big Guns among both the High and Dark Elves ended up beefing each other, afterclaps, with the threat of Slaanesh looming, the elves' ancient war took back seats and the surviving Ulthuani and Druchi formed a truce. The Ulthuani make up just under two thirds of all elves today and the Druchi make up about a third.
There is still lots of tension between Druchi and Ulthuani get along okay bye the bye though we still see the occasional fusses or dust ups.
Sometimes Ulthuani and Druchi get along more than okay if you catch my meaning and you get elves like me. "Quinyar" or "elf mutts" if you perform. I have an Ulthuani mother and a Druchi father. This is uncommon, but we Quinyar's numbers are growing fast, especially in the West.
And to be fair, most dwarves and humans don't care a continental whether an elf is Druichi or Ulthuani and they cannot tell the difference anyway, so they just call us all "elves" and that's fine by me.

Architecture

When Ulthuan was evacuated, a lot of treasures and books were saved, but obviously none of the buildings. Real shame too. Based on the old pictures the elegant towers and arches were slick up superior to anything you see out East or further east across the Pond.

Type

National Territory

Inhabitant Demonym

Ulthuani