I posted the following summary of Gelmorra on my FC sites forums, and thought it would be good to discuss it here as well. If anyone has further insight on Gelmorra or the other ancient civilizations of Eorzea, input and feedback would be most appreciated. The information came from various XIV sites and wikis, in addition to my own experiences in ARR and second-hand information from legacy players. Original post URL: http://gridania.shivtr.com/forum_threads/1556770
---Original Post: Ancient Civilizations, Gelmorra, and the Progenitors of Gridania---
The Floating City of Nym (La Noscea)
Ruins of Sil'dah (Thanalan)
Tam-Tara Deepcroft
It is known that there are at least 3 major ancient civilizations that existed in Eorzea in addition to the Great Allagan Empire. However, where these civilizations place in relation to each other is yet a mystery, though it is presumed that the Allagan Empire was dissolved (4th Astral Era) long before they themselves fell into ruin. Whether or not any of these civilizations reach back to Allagan times is unclear.
Remnants of these civilizations are still prominent in Eorzea today. The civilization of Nym is known for the various ruins left in La Noscea, most notably the end-game dungeon Wanderer's Palace and the nearby Floating City of Nym, while old aqueducts and other remnants of the great city-state of Sil'dih can be seen scattered throughout the southern deserts of Thanalan. It us unclear whether the latter was the creator of the now-sunken Temple of Qarn, or what link it has with the Belah’dian sultans who worshipped there during the Sixth Astral Era. Save some Belah’dian additions to the structure, we do know that Qarn was built long prior to Belah’dian occupation of Thanalan.
The last of these civilizations, the Gelmorra, inhabited the Black Shroud of antiquity and are the builders of the many ruins therein, including Spirithold, the Mun-Tuy Cellars, Tam-Tara, Toto-Rak, and Issom-Har. There is some confusion here as there is also brief mention of an Amdapori civilization in the shroud (builders of Amdapor Keep) which appear to have much in common with the Gelmorrans. As such, it is unclear whether these two people are one in the same, or if they are separate entities entirely.
What we do know concerning the Gelmorrans is that they were a primarily Elezen people, with a large Hyur minority. They may have had a mastery of magitek given the presence of the technology in Toto-Rak. However the origin of these devices is not certain, and it is not known whether Gelmorra developed the technology itself, inherited it from the Allagans, or if the devices found in Toto-Rak were introduced by someone else at a later time (i.e. the Garleans). The Gelmorrans had a strong mastery of magic, though apparently the abuse thereof led to the catastrophic flood which opened the Sixth Umbral Era. This flood forced most of the survivors to seal themselves into the nation's underground structures such as Tam-tara.
The underground exile of the Gelmorran survivors may have led to the distinction between the Wildwood and Duskwight Elezen as phases of emergence and diaspora from the shelters led to distinct evolutionary possibilities between those dwelling above and below the surface. According to the mining leve "Location, Location, Location" obtained at Quarrymill, the ruins of Gelmorra have "served as a necropolis...for half a thousand years," indicating that the last subterranean emigrants exited the caves at least 500 years ago (~year 1000 by the Eorzean calendar).
The first Padjal (the horned, elementally endowed hyur conjurers making up the Seedseers of Gridania) were born during the flood years after survivors banned the use of the old magics and established the art of conjury. It was during this time that these Gridanian progenitors first came into harmony with the Elementals and took on the responsibility of protecting and moderating the aetheric energies of the Black Shroud. It has been indicated that pre-flood Gelmorran society saw racial conflict between the majority Elezen and minority Hyurs, a problem which was also resolved during the shelter years. This new interracial good will is the inspiration for the crest of the Order of the Twin Adder, the two intertwining serpents symbolizing the coming together of equals in the common cause of Gridania.
Two great mysteries that endure today are the Gelmorran links with Ishgard and Odin:
First, it is unclear whether the elezen of Ishgard share a common Gelmorran ancestry, and whether their lineage comes before or after the flood. Given the highly stratified, elezen-dominated nature of Ishgardian society it seems highly likely that any Gelmorran-Ishgardian ancestral link predates the Sixth Umbral Era Calamity, resulting in the many racial stigmas preserved in Ishgard from old Gelmorra.
Second, concerning Odin, it is difficult to place contemporaneously with Gelmorra as his placement within the overall timeline of Eorzean history is unknown. It does seem likely, however, should Odin indeed be some fallen king or sage or old Gelmorra, that his ascension to primal status had some hand in the disastrous fall of the realm. This would also explain his stalking of the Black Shroud, and may even have a tie to Ramuh.
It is unclear what kinds of relations the Gelmorrans had with the old beast tribes, and neither Sylph nor Ixal have as of yet made mention of them.