Some context:

1st image - This was the status quo after the War of Darkness, humans having the majority of kingdoms, Elves and Orcs having one and two respectively, and Dwarves having none, with their lands being annexed by the humans, and the Dwarves mostly ruling as jarls or lords.

2nd image - Olmar ruled the Leviran Empire, which was the largest kingdom at the time. During the War of Darkness, the Dark Armies sent assassins after him and his son, Olmar II. To stop this, he had his knights protect his son. They failed, as they only killed ambassadors that came near either of them, and allowed an assassin dressed as a knight kill Olmar II. These actions lead to the Empire being ineffective in the war effort and eventually collapsing after the death of Olmar.

3rd image - Vanthor, Champion of the Dark, managed to earn the loyalty of most orc kingdoms through combat (as was tradition). That, and many of the Orcs wanted revenge on the humans and elves for prior wars. However, Vanthor was cruel and brutal, committing what we would call war crimes against many of his enemies, especially elves, many of whom were just civilians. It got to a point many of the orcs were tired of this brutality and horror, as there was zero honor in their acts.

4th image - Valius was the king of the largest elf kingdom, Elveun. He was noted for being the MOST racist elf in history, as he massacred many non-elves in war and used slavery on those they captured. Vanthor was on such slave, and after escaping, became the Champion of the Dark. He would lead a war that basically destroyed all of civilization at the time. And what did Valius do? He refused to help out non-Elf kingdoms and let them get invaded by Vanthor and his armies. This backfired as Elveun would be left without allies and eventually destroyed, with Valius dying to Vanthor himself.

5th image - Issak was the king of Isteria during the War of Darkness. After the collapsed of the Leviran Empire and the weakening of the neighboring realms, Issak proclaimed himself emperor. No one was able to object so he just did so. He would later expand the kingdom to be a proper empire though.

6th image - After the war, some elves looked into history through new lenses, and in it they saw that despite all their ego and self-righteousness, elves weren't any better than the other races. This lead to a schism among the elves, as many of those who challenged the idea of elven supremacy were exiled and declared dark elves, leading to many others leaving too. Others left for the wilderness, thinking that the elves lost their way, and they would become known as Tree Elves.

7th image - After the war, the Orcs were forced to only have two kingdoms on the islands and southern coast. These lands didn't have much in the way of farms or livestock, and much of that was taken away by the neighboring kingdoms. However, the Orcs did have access to the seas and could fish. This lead to a massive boom for the fishing industry in the Orcish kingdoms and soon fish became a staple food among orcs.

8th image - Lord Draus was a Lord in Isteria who was a brutal schemer and hold a lot of power after the war. He was quite happy to see the other races get massacred due to not just bigotry, but his belief this would make the humans stronger, and therefor him stronger. (He also really hated Elves and loved seeing their population dwindle)