Human Civilization is one of the participants in the Battle of Divine Will. They can be found in Divine Land's 4 picture scrolls, their representative seems to be constantly changing over the course of history. Their current location is in the southeast of the continent, behind the Impassable Mountains, and Fjord islands in the Vortex sea.
Contrary to demons, witches don't need magic stones to evolve their abilities, but knowledge about their ability and possible way to use them.
Overview
Human Civilization is divided in several societies:
There are also the Fjords islands spread out across the Vortex Sea and Mojin Clan in the Extreme South.
Chronology
Human civilization has been fighting against the demons since the First Battle of Divine Will.
During the first Battle of Divine Will, witches and common people were collaborating to fight against demons, but the core of the fighting forces were witches with their abilities.
The Witch Federation was founded after the First Battle of Divine Will by the survivors, the Union had transformed from an unofficial alliance to a unified political entity.
Humans were led by witches alone, common people didn't hold political power.
After the First Battle of Divine Will they were reached out by the Underground Civilization, and began to slowly discover their technology.
The Witch Federation fought against the demons during the Second Battle of Divine Will, and finally lost after the fall of the last holy city Taquila.
The survivors fled to the Barbarian lands, and established themselves, creating the 4 kingdoms, fjords merchants, and the Church.
With the Witch hunt and the secrets of the Church, the humans lost their knowledge of demons, and witches regressed in their use of magic.
But Roland Wimbledon, gathered witches in the Witch Union, took the throne, and destroyed the Church with the help of Sleeping Spell.
During the Third Battle of Divine Will, groups such as the Taquila Witches, Sleeping Spell, Witch Union, and the Kingdom of Graycastle are united to fight against demons, with Roland Wimbledon as their leader.
They suffered some setback as they were not used to fight against demons, but soon adapted, and took back, the holy city of Taquila.[1]
They are now fighting against demons in the north with the Kingdom of Wolfheart as battle line.
Estimated Age of Civilization in Roland's World
By following the invention of firearms in Roland's World, we can deduce that it takes place 1.1 millennium years before Cheng Yan's age. Just by taking some evidence from this link [[1]], "It may never be known with certainty who invented the first explosive, black powder, which is a mixture of saltpetre (potassium nitrate), sulfur, and charcoal (carbon). The consensus is that it originated in China in the 10th century, but that its use there was almost exclusively in fireworks and signals".