A Tale of Two Islands explains how the Undead Spanish and Undead French came to be
Two middling Pirates by the name of Garcia de Avaricia and Pierre le Porc are self-proclaimed 'Lords' of two small islands in the backwaters of the Caribbean. Each recruit passing sailors, mercenaries, and Pirates as Privateers to guard the waters around their islands and to expand their territories. They issue "letters of marque" (of dubious value) which in turn grant permission for Pirates to fly their flags and sink "enemy" ships with impunity. They promise untold riches, fame and political influence to those who volunteer their services, but these rewards have yet to be granted.
The Spanish Pirate Garcia can be found mainly in taverns around the Island of Isla De La Avaricia carelessly downing drinks and instigating drunken brawls while attempting to coax Pirates into joining his cause. In sharp contrast, the French Pirate Pierre prefers to remain low key and often hides away on his island of Ille D'Etable De Porc. Despite this, he is still somehow successful in enrolling recruits for the French faction. Since their quest for regional control began, these French and Spanish factions under Pierre and Garcia have been at war, incessantly skirmishing on the sea, locked in a stalemate. Little do the recruits know that they are just pawns in a relentless game of chess between the two sides.
Pierre and Garcia take little notice of the many lives lost nor the fact that there is a bigger benefactor to their chaos. Jolly Roger, the vengeful leader of the undead legion, watches the war between Pierre and Garcia from afar, attracted to the carnage between the two factions. He takes advantage of this opportunity to replenish his undead ranks by raising fallen Pirates and enlisting them for his own sinister purposes. Large masses of undead skeletons clad in tattered French and Spanish clothing ceaselessly rise from sunken ships to solely follow the commands of Jolly Roger, oblivious to their previous allegiances. While the two factions squabble amongst themselves, Jolly Roger's minions slowly advance into their territories.