In 2081 CR Gallio joined the Lagorin union. Gallio’s adsorption into the Lagorin empire was not without its difficulties. Many fled what they saw as an invasion, fleeing to the nearby island of Fallanxis. The people of Fallanxia (the only significant settlement on the island) consider themselves the true heirs of Gallio.
Fallanxia willingly joined Lagorin in 2101 CR in a defensive pact against sea-based raiders. The treaty of 2101 CR saw a separation of state and religion with a change in the capital of Lagorin from its home with the shrine of the Tear of Invention to a more central location. It is unclear who the raiders were or where they came from. The last mention of the raiders is in Lagorin military records recording a short and spectacularly one-sided naval battle in 2105 CR.
There are still Fallanxians (Argonian separatists) who wish to see Fallanxis obtain independence and retake Gallio. This is unlikely to happen but it is a constant theme of much of the local culture.
The Argonian Separatist movement
When Gallio joined the Lagorin union It was little more than a very powerful city-state (Gallian) which controlled the Black Swamp and the Argo Forest.
Currently (5122 CR) a movement, calling themselves Argonian Separatists, claim not only Fallanxia but all territory from the Argo Forest (which they spell with an “i”) all the way to the Black Swamp.
The movement itself is largely non-violent but there is a paramilitary wing of the movement that has been responsible for minor attacks on the mainland.
Separatist cells operate in the underworld of Blackgate and Gallian with further support hidden within Argo Forest. Adventuring parties moving through the wildlands here may encounter aggressive bands of humans. A PC group could join the Separatists but this would make them wanted criminals almost everywhere in Lagorin.
Adventuring parties loyal to one of the other two kingdoms may find that the separatists receive secret support as a strong enough separatist presence would allow Hillisk and Feildon an opportunity to take control of disputed lands around Sky Pillar Mountain.