Around four-to-five thousand years ago, a small tectonic shift cause massive underground water reservoirs to open up, raising the sea level and flooding much of the world's land mass. As the sea rose, low-lying civilizations were drowned or scattered, whilst the climate warmed and the ice at the poles began to melt, adding even more water to the ever-climbing ocean. When at last it stopped, the world was forever changed- continents broken apart into massive islands, deserts turned to tropical paradises, and a massive blue ocean lying open, waiting to be conquered.

The great seas of this world are harsh, wracked by massive hurricanes and planetary waves that dwarf anything seen on conventional Earths. Sea creatures grew larger and more aggressive threatening any human who dared set out into the wide blue wilderness. Still, as civilizations recovered, it was those with ships who seized power.

The remnants of Egypt were the first. Having fled their flooded homeland, they moved south into the newly blooming expanses of East Africa and founded an empire there, building towns and cities and monuments, mastering the riverboat and discovering the use of sails. After subjugating the smaller tribes and nations of their own continent, the Pharaohs began to send scouts across the seas, poking at the edges of Asia and the remnants of Europe.

Other civilizations, meanwhile, had not been idle. In China and the island that remained of India, other civilizations had put down roots and begun to spread. The islands of Europe slowly grew into a wide array of warring clans and cultures, quickly developing vessels to fight among themselves. Through all this, the Americas remained almost entirely empty, with the melting of the ice up north preventing early humans from easily accessing those lands.

Egypt first made forays into the European Islands, but was driven back in spite of its superior might and vessels- the European clans were well used to naval warfare after fighting each other for generations on the seas, and were quick to unite against a larger outside threat. By the time Egypt began to adapt, it was too late- the main clans had been united beneath a single leader, who held strong against the assault. Eventually the two sides came to a ceasefire, and trade between them flourished.

India, meanwhile, proved an easier conquest- with a smaller and more peaceful population, it was soon subjugated by the Pharaohs' forces. From there the Egyptian ships sailed on to China, finally encountering another empire of comparable size to their own- but by then internal conflicts had distracted both sides, and so no war between them occurred. Trade routes were established, and both cultures flourished from the exchange.

The newly-formed empire in the European Islands began to expand, conquering parts of North Africa and western Asia. Egypt split into three kingdoms, two in Africa and one in India. A new dynasty took power in China and began to expand, reaching southeast into the islands and westward across the continent until it met and skirmished with the European clans. The clans themselves were beginning to splinter once again, with those who had moved east into Asia forming their own empire whist the rest splintered and fought amongst themselves. Across the world, trade across the oceans thrived- with few land routes available, people turned to ships, which were rapidly becoming faster, more durable, and more widely produced.

It was around this time that a new form of warfare reared its head: piracy.

With the trade boom in full throttle, it spread like a virus. The clans on the European Islands were its main proponents, raiding the ships and ports of the larger empires to sustain themselves, and carving out the first legends of brutal and daring captains. Everywhere else soon followed suit, however, and soon the seas were a battleground, armed convoys competing with pirate fleets competing with powerful navies over the bulk of the planet.

As ships grew faster and better it was only a matter of time before someone discovered the Americas. As soon as word got out, the major empires raced to claim the prizes of the new continents, triggering large-scale wars, civil wars, and generally a great deal of chaos that the pirates profited the hell out of. Many even began to hire themselves out to kingdoms as mercenary fleets, becoming semi-official military forces. By the time the rush for the Americas settled down, the world was further divided, and pirates ruled the seas. Having earned bounties, funding, and equipment from the warring nations, they had become too fearsome and powerful for any navy to stop, banding together and fighting back in huge fleets whenever a Pharaoh or Emperor tried to move against them.

With many of the Earth's natural resources locked away beneath the sea, and huge biodiversity springing up beneath the waves, science evolved with a focus on chemistry, biology, and meteorology. Instead of an industrial revolution, there was an alchemical one, as bright minds took advantage of unique compounds produced by gradually evolving marine life to create new and powerful substances. Explosives and Blood-Powder weapons were already commonplace by the race for the Americas, and afterwards a huge variety of poisons, medicines, propellants, and body-altering drugs began to spring up. The pirates and the land-bound nations took equal part in this, with councils of alchemists competing with crackpot ship-druids to create the newest advancements.

Overall, the world remains in constant flux. Land-bound nations compete with pirate clans for control of the seas, Alchemistry continues to advance in new and surprising directions, and a growing alarm surrounds the appearance of monsters known as Heartless across land and sea, with countries once again recruiting pirates as military forces to combat this new threat.