Encyclopedia - History
Originally, the two Islands were one landmass, forming a ridiculously large Island, close off the coast of the mainland of Temira. Very little is known about this time, except that there was a universally spoken language (now referred to as the Old Tongue) and that magic seemed to be real, powerful and common.
It is equally uncertain what happened to end this time. All that is known for sure is that there was a series of violent earthquakes, referred to as the Rift, and the geography of Temira was greatly changed. The islands were now farther from the continent; far enough so that they lost contact, and there has only been one recorded instance of communication between the two. The one Island was broken up into many, with two main masses—Arpiar and Kalatsu. The language started to change and evolve, until the two Islands were speaking almost completely different tongues, though both had roots in the Old Tongue.
And, more interestingly, the climates of both changed dramatically. Despite being fairly close to each other, Kalatsu and Arpiar were almost polar opposites in terms of temperature. Kalatsu is frigid, parts of it have snow year round; Arpiar is close to tropical, warm year round, and frequently caught in droughts.
History really begins to be recorded somewhere within a hundred years of the Rift—the name given to the earthquakes that change the world so drastically. Somewhere around this time, the first Book of Prophesy was discovered. It seemed to have been written and lost during the Rift, and when it resurfaced it revitalized the religion of Ocando, the God of the Son.
It was an interpretation of the Book of Prophesy that lead to the beginnings of slavery and the war. One of the verses of the prophesy was interpreted as encouragement for Ocando's followers to forcibly convert (or, failing in that, kill and enslave) non-believers. Until this point, relations between the two Islands had been friendly. When Arpiar's forces attacked, Kalatsu was completely unprepared.
Five years after the initial attack, Kalatsu was entirely under the control of Arpiar. From the chaos rose a young girl, remembered as Analla the Sundancer, who was a Prophet of Ocando. She wrote the Second Book of Prophesy, in it detailing the ongoing Rift—now commonly used to refer both to the earthquakes and the war—and how it would be the Third Prophet of Ocando who would end it.
Also in the Prophesy was a description of her own death, at the hands of a dynasty on Kalatsu. Her death, she wrote, would be a sign for the battle to begin again. And, having spread the word, everyone with any blood relating them to the Royal Family of Kalatsu was hunted and killed. While her Prophesy was, strictly, accurate, it didn't tell a full enough story to explain the dynasty. A woman from Kalatsu (by the name of Nyala Kelanister), afraid for her life and her family, prayed to Kaleal for help. Kaleal responded by sending her a young man named Islan. Islan had originally been some sort of Knight on the main continent of Temira, though there had been no contact between the continent and the islands for over a century; he'd fallen from grace at home and had been banished. After several years, he'd taken to a life of piracy, but his ship had been faced with a terrible storm and bashed to pieces out at sea. He'd survived by a miracle, and had washed up on the shores of Kalatsu.
Upon seeing the people of Kalatsu enslaved, he found a chance to redeem himself and return to leading a helpful life. He met Nyala, and they were eventually married; he eventually organized a rebellion that gained strength through Kalatsu. After several years, the rebellion managed to defeat all of Arpiar's forces on Kalatsu, and liberated their country.
Islan founded the Knights, a military branch of Kaleal's Church that fought to protect themselves, their country, and hoped to one day free those still enslaved. Islan and Nyala's son, Alis, was crowned King (and the current calendar began with year one). He pledged himself and his descendents to continuing the fight begun by his parents, and asked the Goddess to tie his bloodline to the Island itself to provide them with the power needed to eventually win the war. To this day, the Kelanister family rules over Kalatsu.
Analla's Prophesy of her own death came true after Alis' coronation. Islan himself had been taken prisoner, and disappeared for a time. Several years later, he reemerged as a slave, spirit utterly broken—or so it seemed. Though no one knew until years later, he had been planting the seeds of an underground network to aid both the Knights and the Kelanister family in their quest. He also eventually murdered Analla, not long before he died.
Things on Kalatsu and Arpiar have remained in turmoil since. The war continues, though at times there have been shaky peace agreements. These are always shattered by a slave raid, even if such a raid was not condoned by Arpiar's High Priest. There isn't constant fighting, though skirmishes happen frequently.
The only notable events happened in the years between Islan's death and the beginning of season one (which starts in the year 360) was a split in the Church of Kaleal. The Knights had always been subservient to the Priests and Healing branches of the Church, and as time went on, the Church as a whole became more focused on Kalatsu and less on freeing slaves on Arpiar. The Knights, as a whole, were frustrated and felt as though they first had to fight their own people before they could go fight real battles. Eventually, lead by Slenna Malistar, the Knights split off from the rest of the Church and founded a settlement on Cresula, the southernmost island in Kalatsu.
And so things stand when the story begins.