Humans were created by their God(s) (according to them). From the very start, they were ill-tempered when it came to dealing with orcs, as the orc's long-standing culture had emphasized strength over weakness, which entitled them to own slaves (dwarves, gnomes, humans, and even orcs and goblins).
Humans fought and claimed their own land, but constantly suffered from raids by Orchans. The Humans were very clever, and proposed alliances with dwarves and gnomes to fight against the Orchans. They promised freedom for all oppressed people. They started what they call the War of Unity, and took lots of land from the Orchans and split it between dwarves and gnomes and humans.
Humans were a strong influence among the races. They constantly pushed for change in order to expand and further their influence and power. During the era of many wars, they attempted to stay together, but disagreements caused different nations to crop up. These nations fought against themselves and against gnomes and dwarves, trying constantly to expand their borders.
During the Draegoni dominion, the humans felt oppressed by the Draegoni control. They were forced to give land to the Draegoni, and they resented them for it. They started lots of rebellions and reunited old alliances in order to conquer the Draegoni. If there is one thing they are good at, it would be using diplomacy to unite and fight against perceived threats.
After the Draegoni fell from power, humans remained as a prominent race on the continent, striving to keep their people on top of the list of most powerful nations. In their weakened state, they sold lots of land to the dwarves and gave other lands to elves and Orchans to appease them. Since then, the humans have fought to reestablish their power and regain lost land, which has caused another era of war and disagreement to emerge.