I'm afraid the jury's still out on that one.
Ala Mhigo is one of the city-states in Final Fantasy XIV. It is located on the eastern corner of Aldenard in a region called Gyr Abania between Gridania and Garlemald. It shares a border with Xelphatol to the north west.
The highlands of Gyr Abania in the eastern reaches of Aldenard were once under the control of a martial nation known as Ala Mhigo. It was, perhaps, the historically conflicted nature of the territory that forged the country into a significant military power.
Even as this aggressive nation sent its forces to conquer in the west, it repelled repeated attempts at invasion from the east. In the Year 1557 of the Sixth Astral Era, however, it finally fell to the incursions of the Garlean Empire. From that time onwards, the country became merely another imperial territory under the governance of its usurpers.
Though the people of Ala Mhigo once revered Rhalgr, the Destroyer, as their patron deity, any such religious observance has since been forbidden by the controlling authorities.
Roughly 100 years prior to the game, Ala Mhigan forces attempted to invade Gridania in a conflict known as the Autumn War. The combined might of Gridania, Ishgard, Ul'dah, and Limsa Lominsa drove them back.
Ala Mhigo was invaded by a technologically superior nation not too many years ago. Though technologically proficient themselves, the largely Hyuran population of the city was still defeated. Those who would not submit to Garlean rule fled west and south, causing what is generally referred to as the "third great Hyuran migration", while those who remained either submitted entirely to Imperial rule or formed the Ala Mhigan Resistance.
But with them, they managed to hold onto their engineering talents. For now, Ala Mhigo remains part of the Garlean Empire. The fall of Ala Mhigo ushered in a change across Eorzea, where the remaining four city-states organized a rough coalition.
Ala Mhigo was inaccessible in version 1.0.
- The fall of Ala Mhigo took place 15 years before the beginning of 1.0, as per quest dialogue (information via npc named Sundhimal during the quest "Winds of Change"). This information coupled with the fact of the time differential of 5 years between 1.0 and ARR would imply that Ala Mhigo had fallen 20 years prior the beginning of A Realm Reborn.
- The majority of all Hyur Highlander clans lived within this city before the time of it's fall.