Beginning of Mobians
In the beginning, mobians were all once just regular animals. One day, they came into contact with the Ancients, aliens who arrived on the planet after the destruction of their home. With them, the animals were able to come into contact with the chaos emeralds just before the Ancients were chased to the Starfall Islands by the humans. After being exposed to chaos energy, it caused some of the animals to rapidly evolve, leading to their anthromorphication.
Despite their evolution, that didn't stop humans from treating them like non-anthro animals (hunting them, using them for labor, keeping them as pets). Eventually, many of early mobians escaped to a far set of islands which they claimed as their new homeland, naming the collective of islands Mobius.
Over the centuries, many mobians would try and make their own civilizations with very little success.
Cores and the Mobian Afterlife
As an effect of being exposed to chaos energy, Mobians have cores instead of souls, balls made from pure chaos energy. Mobians have a connection to Chaos Energy (the strength will vary). When a mobian dies, the energy from their core will return to the chaos energy force or w/e (I don't wanna call it the chaos force as that seems kinda dumb).
And similar to other religions, there is a sort of judgement system that awaits mobians when they die. Given how chaos energy has both positive and negative energies (as established in Sonic Adventure), the type of mobian that an individual was in life will determine what type of energy they end up becoming.
For mobians who are deemed good, they become a part of the positive energies, while positive energy mobians are at peace, they are still able to retain who they were in life. For the mobians who are deemed bad, however, they become part of the negative energies. They don't remember who they were in life. Negative energies become primal husks of their previous selves with no recollection of who they were.
The Acorn Archipelago
The Acorn Archipelago is a series of islands comprising the Kingdom of Acorn. In ancient times, the islands were once a single island named Pancardia, home of the second of the Four Great Civilizations. One night, however, the Second Great Civilization was destroyed, and Pancardia was split into several islands, which are now the modern Kingdom of Acorn. South and Westside Islands are two of the islands apart of the Acorn Archipelago. While the Acorn Achipelago was originally lorded over by King Leer and the hyena tribe, he was dethroned by a resistance led by Alexander Acorn.
The Acorn Family Tree
This is the family tree of the modern royal Acorn family. In order, each of the rulers of the Acorn Achipelago are:
Alexander Acorn: The first king of the modern royal Acorn family. After uniting the separate mobian tribes all over the Acorn Archipelago to form the Kingdom of Acorn, Alexander was named king of his new kingdom and his wife, Angelica, was named queen. Alexander would go on to have three children: Theodore, Edith and Cornelius.
Theodore Acorn: Alexander's oldest son and the next king. He was betrothed to Alice, who he was wed to shortly after his 18th birthday. As king, he continued to manage the Kingdom of Acorn's grow in it's power. Theodore would go on to have two children: Emerson and Diana. While Emerson was initially named the next king, he was tragically shot dead by a human. It was an accident, really: Emerson and that human (a teen boy named Paladin) were messing around with a gun and when Paladin aimed at a nearby Flicky, Emerson took the bullet and bled out. In his grief, Theodore banned contact with the United Federation and banned firearms (until it was overruled during the Great War).
Diana Acorn: The first Acorn queen born into the line. Diana was born later in Theodore's life. And despite being a female, she was made queen of the Kingdom of Acorn shortly after her father's death. She was married to William. Together, they had Julius.
Julius Acorn: Due to being so unprepared for being queen, Diane spent most of her time preparing her son for his role as king. Following a near death experience as a young man, Julius became very religious and introduced a number of religions into the kingdom. He was betrothed to Julia. Julius would have two children: Romulus and Aelia.
Romulus Acorn: The 4th king. As king, Romulus spent his time, building up the kingdom's power and authority. He made very well sure that he was viewed as a good ruler. He was betrothed to Rhea. Together, they had George.
George Acorn: The 5th king. George was spoiled rotten by both of his parents. So much so that he deemed himself perfect. Under this delusion, he started a war with the United Nations (King George's Folly). Due to losing war and a variety of other bad decisions, the court deemed him unfit to rule and rendered him powerless until his passing. He went to the grave thinking he had no faults. George has 6 ex-wives (yes, this is a reference to King Henry's 6 ex-wives). The first was Catherine (chipmunk), a noble from a colony in Efrika, who he was initially betrothed to before he began seeing Anne (the Skunk), a noble from Eurish (in the Sonic equivalent of France), who became his 2nd wife. He then began seeing Jane, a noble from Avalon, who died shortly after giving birth. Then, he married Maria, a noble from the Sonic equivalent of Germany, before he began seeing Joyce, another noble from Avalon, before he ended up with Maud. Maud was his wife until the day he died. George would have three children: Elizabeth, Margaret and George I.
Elizabeth Acorn: The 2nd Acorn queen. George I, George's only son via Jane, was killed during the war. Margaret, George's youngest daughter via Anne, mysteriously disappeared during the war. With no other heir, Elizabeth, George's eldest daughter via Catherine, was made queen. Disgusted by her father's actions, she spent most of her time mending the relationship between the Kingdom of Acorn and it's citizens and rebuilding the kingdom from the war. She was betrothed to Walter. Together, they had Reginald.
Reginald Acorn: The 6th king. Reginald was a romantic at heart who loved to write poetry. He ushred in a new wave of arts exploration in the kingdom. He was a bad poet. Instead of being bethrothed, he married his wife, Caroyln, after meeting her during a trip to a colony in Tralius. Reginald had three kids: twins Silvanus & Silas and Christina.
Silvanus Acorn: As the older twin, Silvanus was made king. Not feeling like the kingdom was doing enough, he made a lot of questionable decisions in order to strengthen the kingdom's authority and control. He was betrothed to Loida. Silvanus had two daughters: Charlotte and Katharine.
Charlotte Acorn: The 3rd Acorn queen. Due to having no male heirs, Charlotte was named the next queen. As queen, she tried to quickly broker peace with the United Nations. It was often speculated that she only did this just so she could travel the world. During her travels, she met and married Charles. Charlotte had two children: Frederick and Rosetta.
Frederick Acorn: The 7th king. As king, Frederick endured the Great War with the United Nations. Despite the conflict, he was extremely open and welcoming during his reign. Following Alexander’s example, he tried to open his kingdom to new people and ideas. He was betrothed to Helen. Frederick had three children: Nigel, Max and Julayla.
Nigel Acorn: The current king. Nigel is the current king. Following his father’s example, he welcomed individuals like Dr. Robotnik and Naugus into his kingdom…only to be betrayed by them. Spent time in the Special Zone until he was rescued and returned to his throne, where he rules to this day. He was betrothed to Alicia. He would go on to have two children: Elias and Sally. Max, meanwhile, choose to travel the world where he met Bianca. Max would go on to have two children, Richelle and Tuftee, before he passed, leaving his young children under the care of their uncle. Julayla, meanwhile, dedicated herself to becoming a mentor to her niece prior to her passing. She was extremely close to Rosie, her cousin via her mother.
The Great War
50 years ago, the President of the United Nations declared war against the Acorn Archipelago after generations of tension between the two communities. The war lasted for 5 years. During this time the United Nations, with superior technology, took over Mobotropolis and sent the mobians into hiding. While they were eventually able to reclaim Mobotropolis, the mobians were losing the war until a UN defector gave them the tools they needed to turn the tide against the United Nations. The outcome of the Great War was determined between a sword fight between the President and King Frederick with King Frederick winning the duel and forcing the United Nations to retreat.
The Winter Acorn Festival
Instead of Christmas, the Kingdom of Acorn celebrates the Winter Acorn Festival. The Winter Acorn Festival celebrates the founding of the Kingdom of Acorn.
Before the Kingdom of Acorn, the mobian tribes on the Acorn Archipelago were being lorded over by the hyena tribe (led by King Leer). And because each of the tribes kept to themselves, it was easy for King Leer to keep the other mobians oppressed.
But when a group of mobians came together (led by Alexander Acorn), they dethroned King Leer and the hyena tribe disbanded. Seeing how well the mobians could work together, Alexander rallied the mobian tribes together to found Mobotropolis.