Islamic Involvement in west Europe 711-1492 explained(Using Revolutions mod, etc.):
The Arabs, combined with Carthaginian mercenaries, have landed in Taifa. The Great General, Tariq ibn al-Zayid, deleted his galleys and urged the troops to capture all the independent states in the region, which was done easily.
The Arabs have conquered all of Iberia, and were finally held back by the French, who stopped being independent states and united under France. The French spammed spearmen stacks, with the Great General, Charles Martel, joining a group of swordsmen. The Arabs, having armies mostly consisting of camel archers, Numidian cavalry and horse archers, could not decimate the French defence, and were forced to retreat.
Arabs slowly spread Islam throughout Iberia, and it became the dominant religion of Iberia. The Arabs, with their land in most of the mediterranean, had great potential, and teched optics, education, astronomy, gunpowder, engineering and machinery.
Unfortunately, Arabia did not have mercantilism or state property enabled, so maintainance costs started to become very high. Arabia could no longer afford to do deficit research, and was forced to keep research at 10%, and eventually stopped teching.
In an attempt to raise stability, Arabia gifted their cities in Iberia to Carthage and gave Carthage all the techs they have researched. Carthage is already struggling in stability, so having all these cities made it worse for Carthage. Arabia also gifted their camel archers and Numidian cavalry to Carthage, making it difficult for Carthage to improve its economy.
This caused many of the northern Iberian cities to become independent. Zaragoza was one of these cities where Carthage kept their cavalry, a military base defending against French forces, which were beginning to get influential. Zaragoza revolted, and became the sovereign city state of Spain, taking plenty of Carthaginian and independent cities in an attempt to unite Iberia under Christianity. France fully supported this new state, and declared war on Carthage to capture cities to give to Spain.
Lisboa followed Spain's revolt, and became the sovereign state of Portugal. Lisboa contained Carthaginian caravels and crossbowmen, which joined the Portuguese.
Spain was conquering most of Iberia, taking cities one by one, always remembering to drop an inquisitor to each conquered city. Portugal has done the same, except on the west of Iberia, and also permitted Spanish inquisitors to take out heathens.
Seeing Carthage's inability to defend it-self, Arabia sends in some camel archers which are destroyed by endless hordes of Spanish swordsmen.
Eventually, Carthage lost all cities in Iberia save for Granada, the only remaining city. Carthage signed a peace treaty which agreed to give both France and Spain optics, education, astronomy, gunpowder, engineering and machinery. The treaty was signed, and Granada was eventually taken by Spain through cultural domination. Islam and Judaism get officially expelled from the sub-continent.
Portugal, France and Spain, using Arabian technology and equipment, explore the new world.