The Ancient Era
The period of time in which the Ancient civilisations were most active. It was not known as the Sea of Thieves back then, but these peoples had a greater understanding of the world within the Shroud than us pirates!
The Forming of the Devil's Shroud
The Devil's Shroud, the name given to the impenetrable wall of fog that surrounds the Sea of Thieves, has existed since prior to Ancient times. How the Shroud came into being is currently unknown.
The Ancients used artefacts like beacons to protect their homes and places of worship from the Shroud's effects or created relics for safe passage into the fog.
As the Devil's Shroud formed, cutting off access from the outside world, the Sea of Thieves is now trapped within this bank of impenetrable fog.
The Civilisation of the Ancients
The First Ones. The Lost Tribes. The Ancients. Whatever you call them, they were earliest known inhabitants of what we now call the Sea of Thieves.
Signs of their civilisation can be found all over: cave paintings, potteries, and other artefacts. They built temples, altars — places that were important to them. The Ancients had ships and even a few pirates. There were also artisans and sculptors, philosophers and painters. Their currency was possibly the Ancient Coin, a rare coin emblazoned with what appears to be a skull.
They were an intelligent and creative community, that charted star constellations, told stories, and became aware of the magic that the Sea of Thieves offered. As they mastered the use of magic, they created specially imbued relics such as the 'Shroudbreaker'. They have also been claimed to have used Kraken Ink to see the future, much like how the Order of Souls use Kraken Ink in recent times.
Within their culture, specific titles and roles were given to chosen individuals who lived up to their potential. Such known roles are the Warrior and the High Priest. Some individuals even took on the mantle of sacred animals that were represented in the star constellations.
It is unknown if they were all one united people, or if they lived in different tribes. The monolithic statues found on Tribute Peak at least suggest that there were ten key figures in their society.
The Ancients sought to reconnect the two worlds
An Ancient Priest sought to reconnect the worlds of the Sea of Thieves and the Sea of the Damned once more. The outcome of this remains unknown, however the Priest understood that the two worlds must remain parted to preserve the balance with a world of the living and a world of the dead.
The Ancients destroyed the Veil to prevent its power from falling into the wrong hands. They fed the headpiece to the Shrouded Ghost and hid the stones where they would never be discovered.
The Civilisation of the Merfolk
The Ancients were greatly appreciated by the mer people. The latter used to uncover precious stones and gems in the very deepest parts of the ocean to bring them back to the meeting places as a gift.
The Mer communicate with sounds that are unintelligible to humans, this language is referred to as their 'Song'. With the purest pearls, the Ancients crafted magical earrings that allowed them to hear the merfolk song and be understood in kind.
Old Mother — the oldest and largest Kraken known to have existed — had a relationship with the Sea Queen — a monarch of the Merfolk — but became angered when the Queen 'broke her promise'. Possibly due to this breaking of a promise, Old Mother used to feast on the Mer. The mighty Kraken woke every century or so to feed and before settling back down to sleep again.
A Forbidden Love
There was once an ancient Warrior who fell in love with a Sea Queen of the merfolk. Their love was all-consuming and neither could imagine life without the other so they began to search for a way to bridge the gap between their two worlds. The Warrior was willing to do anything to be by her side and attempted to harness the powerful forces of the Sea of Thieves.
The Ancients feared what would happen if the Warrior was to upset the balance of the Sea of Thieves. To put a stop to it, the Ancient King sought the assistance of the High Priest to prevent the Warrior from meeting with the Sea Queen. The High Priest used a potion to change their voice, mimicking that of the Sea Queen and lure the Warrior to an unknown island. There, the High Priest attempted to poison the Warrior with an arrow. The High Priest was not successful however, as the poison was not enough to put down the Warrior, and they were flung from the cliff and into the sea.
The Whispering Plague
The merfolk possessed stones that could hold powerful magic and the Sea Queen believed it was these that would bridge the gap between her world and the one of her lover. The Warrior and the Sea Queen believed their love was strong enough to survive the consequences for breaking the sacred rules of their people. So the Sea Queen used a Mermaid Gem to turn her lover into a merfolk.
The transformation was successful but unleashed a terrible curse that robbed the Queen of her song. The curse became known as the Whispering Plague and could be transferred by a simple scratch, spreading quickly to the Sea Queen's people.
The Song of a merfolk is part of who they are, their soul and their collective memory. Without their song these merfolk became something else, something twisted and leaving only darkness.
Those afflicted were exiled, likely as a preventative measure to keep it from spreading. This new branch of merfolk became known as the Sirens. When they found their voices once more, theirs was now a song of sorrow — the Siren Song — a grief for all that they had lost.
The Chaining of Old Mother
The Merfolk tried to fight Old Mother, but unsuccessfully. Eventually, they sought help from the Ancients to find a way to be rid of Old Mother.
According to tales passed down in the stars and in cave paintings, a Warrior known as 'Warmonger' fashioned poisoned arrows from feathers stolen from Eagle and drenched with venom from Snake. But not even the most powerful magical weapons would have been enough to deal a mortal blow to Old Mother. Instead, these arrows put it into a deep sleep and she sank to the ocean floor. The Ancients then forged great chains to bind her and placed a curse on them. The links could never be broken, and the locks would never rust or be broken. Old Mother lay there, trapped, until she died.
The Fate of the Siren King
The Siren King was met with hostility and chained up and bound at the behest of the Ancient's Ruler, fearing and coveting his power. This sparked a war between the Sirens and the Ancients as the Siren Queen sought to bring her King back. Eventually the Ancients sealed the chained Siren King in one of their Vaults, and bound his soul to a chest which later became known as the Chest of Eternal Sorrow.
The War Below the Waves
After the chaining of Old Mother — the mighty Kraken that the Sirens had begun to treat with a devotion that bordered on worship — and bounding the Siren King's soul into a chest, the Ancients found themselves embroiled in the war of the Merfolk against the Sirens.
To expand her army on land, the Siren Queen bounded the souls of the Ancients she caught into Mermaid Statues. With the power of the Mermaid Gems, she turned them into what she called Ocean Crawlers and corrupting the gems — now know as Siren Gems. Nowhere was safe, on land or sea.
A Warrior vowing to end the war once and for all, took up her blade and strode fearlessly into the sea, forcing the Sirens to retreat into the darkness. The Ancients used Mermaid Gems to hold an immense power that forced the Sirens to slumber.
Once the Warrior returned home, she brought back with her the curse of a sunken sorrow. The Ancients entombed her remains into the vault of the Shrine of Ancient Tears and sealed it for the danger it contains.
Shrine of Ancient Tears, Journal: War Below the Waves