Unlike the other nations of its time, the seafaring nations were weak in war. Many were fierce and brave warriors, but not much beyond it. It might be due to the constraints of being separated by the seas, or the humid and hot nature of their climate bringing expedition expenses to an expensive high, that the wars that they waged against each other were small in scale, whereas the continent would easily be able to send out a hundred thousand men, the islands would only have wars involving a few hundred select warriors. Wars were not worth the effort, and the science behind these wars did not develop. But this weakness and relative peace came with a price, the archipelago was home to a variety of unique and flavorful spices, and unlike the mercury that filled the flasks of the alchemists, or the iron that were could be reforged from every piece of broken steel, these spices were consumables, they spoiled and remained priceless. It was not long before the islanders were destroyed by outsiders, and after the first outsiders fell, the continent took hold of them. Centuries passed in bondage, centuries passed into freedom, and back into bondage, and before long they developed their own acuity. In a world where they were weak, one had to become opportunists.
There were many kingdoms that gained their independence during the reign of the Empire, but many, they said, were secretly vassals. The Empire, long knowing that direct rule would not favor their resources, elected to tie down the archipelago with illusory power. Most commonly, the Empire would grant false sovereignity to a fief, concentrate political power to a single ruler, and tie down that ruler with a noose made out of carefully crafted tools. Kings would be deposed by their subjects, simply through the spreading of strategic information under the Empire's spy network. The church, on the other side of the equation, made sure that the slaves and peasants reacted in the exact way how they were supposed to be: as useful idiots.
It was high noon, and the scorching sun made it unbearable. But the actions of the Empire were blind to its own shortcomings. As these places changed hands, many of these nations started becoming aware. It took only a few wise rulers to look further into the future to unravel the rope around their neck. But it did not happen in a single generation, there were allies to consider, and who they needed to face, and the cost of resistance against them... these were not something that they decided on a whim.
"What is freedom? It is the sea."