Here's a little thing from our NESer game of multiplayer EU4.
I am playing as the Bretons, who have built a massive colony called Francisiane, or Fransezh. After making their first colonies in the Breton Antilles, Brittany went on to settle New Nantes (Naoned Nevez) at the mouth of a giant river. At the dawn of the 16th century, the Papacy granted the Duke of Brittany the exclusive right to Christianize and settle the region drained by this river, which was at the time still a vast and unexplored expanse.
The colony grew quickly, encountering only a few hiccups, including a large native alliance that for a time halted its inland expansion. However, it steadily expanded, and Breton explorers mapped the interior of the continent of North Similian.
In the mid 16th century, France joined the colonial game in North Similian, seizing a Portuguese colony to establish the territory of Floride. This upset the Bretons, who had come to see North Similian as their area of exclusive influence. Papal diplomatic intervention led to the First Treaty of Avignon, which clarified that the Francisiane grant referred specifically to the lands draining into a stretch of coastline between the OTL Pecos and Chattahoochee Rivers, and that the Bretons possessed no exclusive rights to the continent. Thus, an invisible line stretching from the northwestern edge of the Floridian peninsula and through the Appalachian mountains came to be understood as the border between the French and Breton colonial regions.
For a time, the two regions grew in peace with one another. In a separate war, Brittany acquired the island of Vinland from its Norwegian owners, renaming the island 'Douargwin', a direct translation of its Old Norse name. The Bretons also actively campaigned against the native federations of the southern Appalachians, expanding their colony further to the east. The establishment of a Breton settlement at Tadoussac drew protests from the French, who believed that they had right to all of North Similian that drained into the Atlantic Ocean. Other conflicts arose in the Ohio region. Due to its proximity to French settlements on the eastern seaboard, France opined that the Ohio territory ought to belong to Floride, while the Bretons argued fiercely that the Ohio river drained into the Mississippi, and was thus an integral part of their initial papal grant. Improved mapping of the continental interior led to the discovery of the Chicago River, forming a tenuous connection between the Mississippi and the Saint Laurent. It was this connection that the Bretons used to claim Douargwin-Veur (OTL Canada) as an extension of their colonial grant, proposing the first complete colonial border, stretching from the Chattahoochee River, through the height of land of the Appalachians, then jogging up to Lake Erie, then following along Saint Laurent's River to the sea.
All of these disagreements ultimately necessitated the Second Treaty of Avignon, which further clarified colonial regions of influence. Brittany maintained its island colony of Douargwin, but surrendered Douargwin-Veur and the Tadoussac colony to France, which became the basis of the French colony of Cockaigne. Brittany reaffirmed its claims to Ohio, and the Pope granted the Mizhigan Territory, the lands immediately south of the upper three Great Lakes, to the Bretons. Furthermore, the Hurons, who found themselves sandwiched between the two colonial rivals, were designated as a realm which would belong to neither colony, but would rather be Christianized and permitted to remain independent. The Bretons were quick to enforce this decision, and the Hurons would subsequently fall largely into the Breton sphere of influence.
The Second Treaty of Avignon also proposed a line, driving due north-south from James Bay to the edge of Lake Huron, to divide Douargwin-Veur between Breton and French regions. Neither side could agree on a border, with the Bretons claiming that anything draining into the great bay to the north was, in fact, draining into the Arctic Ocean and thus not subject to French Rule, while France went as far as to claim all lands north and east of the Mississippi watershed as its rightful territory. This proved to be an unresolved sticking point which remains contested to the present day.
Finally, the Treaty sought to specify a fate for the mighty empires of the Nahua and Maya, although neither France nor Brittany seemed particularly eager to take on these formidable states. Perhaps as a result of this reticence, the Papacy established the Knights of Saint Mary, a crusading order which would, in the following decades, war against and subjugate these heavily-populated pagan kingdoms.
It was during these Catholic wars for Mechiko that the southwestern portions of the colony of Francisiane shifted away from the central colonial authority in Naoned Nevez. A collection of Breton farmers, miners and ranchers formed an unlikely alliance with previously-conquered Pueblo and Navajo people, and began to report directly to Brittany, rather than to the colonial capital of Francisiane. Brittany accepted this and recognized the distinct colony of Mechiko, while to this day, Francisiane continues to view these provinces as de jure parts of their country.
One major impact of the establishment of Breton Mechiko was the end of southwestern expansion by Francisiane. Instead, the Bretons turned to the northwest, pushing further up the Missouri River and across the continental divide. Here, they encountered an English colony, California, spread up and down the Pacific Coast of North Similian. Bretons have warred inconclusively with the English Protestants of both California and Texas, although as of yet no lands have yet changed hands.
Today, Francisiane stands in a unique position. It is the crown colony of the Breton people, and already significantly outpopulates its mother country. The colony has a historical French-speaking elite, but much of the population speaks Brezhoneg, a Celtic language, or native patois. Borders on the ground are frequently not in alignment with those seen on maps, and in several cases Francisiane has exceeded its initial land grants, while keeping stringently to the word of its promises (Bretons never
settled these regions, but they did battle the natives who lived there, then claimed their land by right of conquest). Expansion further south and west is blocked by stubborn Mechiko and the English, while eastern expansion is blocked by treaties with France and the papacy. Today, many Bretons look north, to the vast wilderness of Kiskachewanezh, for further expansion.