The Conflict
Prelude
The Frontier Princes have always been known to be a place of lawlessness, but few dared to venture there. That is until Pope Justin Marfont, would meet with some advisors upon a plan to expand the church's influence even more. While Vebastonne and parts of Rusilvaynia proved to be troublesome, the Frontier Princes were comparatively easier to influence. However it seems all attempts at peaceful integration were rebuffed, with one Lord Volkmar Kersting sending a particularly nasty refusal. Always being one of short temper, Pope Justin would call for a crusade force to march into the frontier princes, using hep from the Bolsilvans of Ustaria to move through, and promised not only absolution of ones immortal soul, but the promise of great wealth.
Using the pathways granted to the Church via Bolsilva, the Crusaders would march into the Frontier Princes with minimal attritional losses, and set to conquering every city state they came across. Meanwhile, the Frontier Princes were at first surprised, but Lord Volkmar managed to use a series of favors and mutual cooperation to, for the moment at least, unite much of the Frontier Princes to fight back.
Fair, save for a few freak arcane storms and heavy rainfall and muddy terrain, some areas were swampy and so were particularly bad to fight in.
While for the most part the Crusaders managed to gain much territory. Progress stalled as they were dragged into multiple prolonged sigies at once. Progress effectively ground to a halt as the Crusaders would skirmish with outriders and try to batter down the walls. However the Frontier Princes were proving to be stubborn and held firm. However, the decisive battle the Church was looking for was found when a sapper team managed to blow an unexpectedly large gap into the walls of Lord Volkmar's City state, leading to Crusaders to rush the gap and manage to take it. Volkmar was said to be impaled on a spike on the highest building at the end of the siege, and the Crusaders used the city as a base of operations. With the one unifying thing the Entente had, many fell to infighting due to past grudges, which led to many of the city states proving to be easy pickings for the Crusaders. Eventually, the Crusaders realized they couldn't effectively push any further while holding their territory, so with Pope Justin's blessing, the crusade was officially ended.
The Church would manage to establish several Crusader States taking the place of the city states, and would bring the light of the Flame to the Frontier Princes. This was also a highly lucrative crusade as many of the rouge princes and tyrants held much wealth in their vaults.
Ironically, after 500 years, many of these Crusader States would begin to decline due to a variety of factors ranging from civil unrest to economic turmoil. Nowadays there only remains 2 Crusader States still active, which means the Church's power over this lawless land is very minimal. However worship of the Light Pantheon has become more popular in the Frontier Princes as i direct result of the Crusade.
Historical Significance
The Church holds it as a valiant charge of godly men and woman against pagans and non-believers, and was a means to secure the land lest they be corrupted by devil worship and other vile things.