History (or check out the timetable)

Pre-history

The first sings of people living in Rainbowisland appear somewhere between 7000 and 5000 BC.
Very little is know about these people (called proto-islanders). What is know, is that they first arrived on the north-eastern shores of rainbowisland and spread west and south from there. Studies of bones of these people suggests that at least some of them were of eskimo blood. But these findings are not conclusive. There is no evidence of a central government and they did not have a writing system.
Evidence suggest that they preffered to live on the coastline. At least 90% of their tiny villages was within sight of the Atlantic. Their houses were made of animal skins but they also used seaside caves as a dwelling. They were able to build simple wooden houses, but they very rarely did (it has been suggested that they used wooden houses as temples, due to the high number of artifacts found in these houses).

The proto-islanders prospered and with time, settled along the entire coastline of the island. The total polutation remained small (a village typically had less than 50 people living in it)

In 1678 BC, the first wave of imigrants came. (there are 5 waves in total)
It is almost certain that the new arrivals were Ancient Belgians. What they were looking for and why they were looking for it in the middle of the Atlantic is unknown. Hesitant at first, the Belgians soon started poaring into the island. (there were families who made a living simply by sailing with imigrants to the island and back with jewels, metals, furs and feathers). Some of the Belgians set up villages on the coast, but most went in-land. Where population pressure got to big, wars broke out between the Belgians and the proto-islanders, always ending in defeat for the proto-islanders (they were inferior in numbers and weapons technology).

In time, the proto-islanders disappeared. Some villages were destroyed, but most were swallowed up by nearby Belgian villages.
Although at first, the Belgian were all ruled by the same chieftain, this did not last. New arrivals had their own chieftain and remote parts of the lands elected a local warrior as chieftain. The original tribe, the Tribe of the Fathers, was eventually limited to modernday Kastelia.
The Ancient Belgians (who by now regarded themselves as "Islanders") were able to colonize the entire country and the islands around it. (except for modernday Lismenst, which was a Holy island, only to be visited by druids). They remained undestirbed for centuries.

Historic Ancient Times

In 54 BC, Roman legions under the command of Julius Caesar invaded Belgica. News of this event was slow to reach Rainbowisland. Actually, the first news that did get through were the reports of the victory of Ambiorix against the Romans. Soon, however, the news got worse. New Roman legions were winning the war. The tribes of Rainbow island agreed to go and help the motherland. In 51 BC, the great battle of Belgica took place. A combined army of Belgians and islanders (mostly Kastelians, Montanans, Craw and Southlanders, but every tribe contributed to the army) under the leadership of Ambiorix, was outnumbered 3-1 by the Roman legions. The battle lasted for 2 days and 1 night and was decided when fresh Roman cavalery took the field. Over 80% of the combined army was destroyed. The Belgians fled into the swamps, the Islanders fled to their boats. A heavily wounded Ambiorix was taken by a group of Montanans to Rainbowisland. Several tribes of Rainbowisland planned an invasion to free Belgica but noone would accept the commands of another chieftain. One attempt was made by the Eastsea tribe but it failed horribly. In the end, the islanders gave up. They were aware that the Romans would be comming and that they could do nothing to stop them. Ships were sent out in search of allies and better weapons. All they could do now was wait.

Roman Invasion

In 26 BC, a Roman legion landed on the holy island of Lismenst. The only people they encountered were a group of druids performing a ritual. They killed most of the druids and captured the rest, also destroying their boats to prevent anyone they might have missed from escaping. According to legend, one druid did escape and swam all the way to Ta Valta, warned his tribe and died, probably of hypothermia (it is very likely that he used a boat in stead of swimming and survived, it is belived that this legend was modeled after the Marathon story of Ancient Greece).
Before the tribes had time to meet, the Romans had already conquered all the islands of Ta Valta. Seeing their closest brothers enslaved, the tribe of the south launched a counterattack which failed misserably.
All the tribes agreed to fight the Romans. An attempt to appoint one leader failed. As a result armies coordinated badly and there was a lot of strife between the allies.
In 25 BC the Roman invasion of the mainland came. The handfull of armies that was in the right place got slaughtered. New arrivals attacked the Romans as soon as possible. The Romans easyly defeated these small attacks. By the end of 25 BC, the Romans had conquered 50% of modernday Kasen. The tribes used the winter to fortify their positions and to get a defence organised. Some armies joined together and by the end of the winter, 9 warlord had assumed command of the armies of Rainbowisland.
Still, bad communication between these 9 armies weakened them. By the end of 24 BC all of modernday Kasen, the east of Puipil, the south of Kastel and all of Eastsealand were lost. The Tribe of Fathers survived thanks to their position on top of Ambiorix Hill (modernday Kastelia).
In the winter of 24 - 23 BC, a ship sent out in 27 BC returns to Rainbowisland. On it, are Gorrix and Lirix, the twin sons of Ambiorix. Gorrix and Lirix succeed in uniting the tribes just as their father had done in Belgica in 53 BC.
The twins start organizing the armies. They also began useing some of the knowledge they gathered in Greece. By the end of the winter, Rainbowisland was able to field it's first ever phalanx. For the next ten years, Rainbowisland and Rome were locked in a fierce battle. With time, the islanders started implementing more and more of their acumulated knowledge. After the Phalanx, they started useing legions, archers, basic cavalry, rudimentary catapults, something similar to Greek fire and some inventions of their own (nocturnal warriors, attack dogs and a sticky liquid that smothers fires). The most powerfull weapon Gorrix and Lirix had brought back from Greece was a writing system. Up until then, sending orders over long distances depended on the memory of the messager. Those who had learnt Greek now thought a limited version of it to the commanders in the field. Now the exact words of Gorrix and Lirix reached their commanders. It was also possible to use messager dogs in stead of humans to send messages.
In 13 BC the Romans tried to bribe some of the tribes away from the alliance during "peace talks" and when this failed, they tried to kill Gorrix and the generals who had acompanied him to these talks. Faced with this treason, Gorrix picked up a spike on which chickens were roasting and stabbed the Roman governor with it, nailing him to the door of his own palace. Nailing a chicken to the front door has been used as a declaration of war ever since. The Romans had collected most of their army at the foot of Ambiorix Hill intending to attack the Tribe of the Fathers once the generals had been bought or killed. Unknown to the Romans, the Islanders had also assembled their army and in the following night, the Islanders attacked. The result was the biggest defeat the Romans had ever suffered. For most of the battle, rain poured down, but during the final hours of the battle, holes started to appear in the couldcover. And a rainbow appeared (rainbows are a very common sight during spring in Rainbowisland). The tribes saw this as a good omen and doubled their efforts. The battle would later be called the battle of the rainbow.

Pushing back the Romans

Gorrix and Lirix were both seen as the reason for the victory of the tribes. They were quick to capitalise on their new found importance and managed to get the tribes to agree to make every effort to liberate Belgica (which they still considered their homeland, despite being born on Rainbowisland). It was even decreed that the tribes would not stand as one until Belgica was liberated. This agreement was later refered to as the pact of unity. Gorrix and Lirix had high hopes that they would see their homeland liberated in their lifetime. In the end it took 1842 years before Belgica would be free.

First things coming first, there were still Romans to drive out. Rome learned of the defeat and sent a new army. But by the time this army was ready and enough boats had been assembled to take it to Rainbowisland, it was late autumn. The generals stationed in Rainbowisland adviced against sending ships so late in the year (they knew how severe the storms can be around Rainbowisland in those months). The ships were sent anyway.
5 days sailing from Lismenst a storm hit the fleet. It was not an exceptionally bad storm, but the Roman ships were built with the relatively calm mediteranian sea in mind. Out of the 127 ships, 37 sank outright and a further 17 were so badly damaged that they could no longer be steered. Only one of these ships was ever seen again. The remaining 83 ships were badly dispersed by the time they came anywhere near Rainbowisland. Although the southern tribe had a small navy, it's ships were well adapted to the weather around the islands. They met the enemy about half a day sailing from Lismenst. The southtribe ships could easyly choose which ships to attack and in this way, they were able to sink 41 Roman ships and damage another 18. None of these damaged ships survived the storm which was still raging. The southtribe navy had an improvised but very effective catapult ship. The bow of these ships was extended and cleared of every object.