THE CROWN OF ARAGON

The Crown of Aragon was a composite Monarchy, referred to as a confederation of individual polities or Kingdoms ruled by one King with a personal and Dynastic Union of the Kingdom of Aragon and the County of Barcelona.
In the 14th and 15th centuries, at the height of its power, the Crown of Aragon was a state with primarily Maritime Realms, controlling a large portion of present-day Eastern Spain, parts of what is now Southern France, and a Mediterranean Empire which included the Balearic Islands, Sicily, Corsica, Sardinia, Malta, Southern Italy (from 1442) and parts of Greece (until 1338).
The component Realms of the Crown were not united politically except at the level of the King, who ruled over each autonomous polity according to "its own laws." The different lands of the Crown (Kingdom of Aragon, the Principality of Catalonia, Kingdom of Valencia) functioned more as a confederation.
The political center of the Crown was Zaragoza, where the Kings were crowned. The city lies by the Ebro and its tributaries, the Huerva and Gallego, in the center of both Aragon and the Ebro Basin.
The city was called by the ancient Romans "Caesar-Augusta." Augustus founded the city (it is known between 25 to 12BC) and used the same location to settle army veterans from the Cantabrian Wars. The Wars were the final stage of the 200 years long Roman Conquest of Hispania, in what today are the provinces of Cantabria, Asturias, and Leon, in NorthWestern Spain. This Warlike Peoples presented fierce resistance to Roman domination. More than 50,000 soldiers were needed to subdue the Region. The Emperor himself moved to Segi-Sama (modern Sas-Amon, Burgos), to supervise the campaign personally. The major fighting was completed in 19BC, although there were minor rebellions until 16BC and the Romans had to station 2 Legions (X Gemina and IIII Macedonica) there for 70 more years.
Long before the First Punic War (264 to 241BC), one of three wars fought between Ancient Carth-Age and the Roman Republic for the supremacy, primarily on the Mediterranean Island of Sicily and its surrounding waters, and also in North Africa, between the 8th and 7th centuries, the Phoenicians (and later the Carthagenians) had already appeared in the Southern part of the Iberian Peninsula as well as in the East, to the South of the Ebro, one of the most important Rivers of the Region and the 2nd longest after the Tagus and the 2nd biggest both by discharge volume and by drainage area after the Duero.
Their numerous commercial settlements based throughout these coastal strips provided an outlet into the  Mediterranean commerce for minerals and other resources. This had the indirect effect of the native peninsular cultures adopting Eastern characteristics. Phoenician trade in the Peninsula included articles both coming from and heading to Greece. As a commercial power of the Western Mediterranean, Carth-Age expanded its interests to the island of Sicily and the South of Italy. This growing influence over the Region proved to be an annoyance for Rome. This conflict of commercial interests led to the Punic Wars. A decisive defeat for Carth-Age at Zama wiped the city from the historical scene.
The battle was fought around October 19, 202 BC. A Roman army led by Publius Cornelius Scipio Africanus (Scipio), with crucial support from Numidian leader Masi-Nissa, defeated the Carthaginian Force led by the commander Hannibal, despite Hannibal possessing numerical superiority. This was because many in his army were recent conscripts, and the vaunted Numidian Cavalry (Mercenaries) which Hannibal had employed with great success in Italy had by then switched sides to the Romans.
Despite having vanquished their rival Mediterranean power, the Romans still took another 200 years to bring the entire Peninsula under their control through an expansionist policy that earned the enmity of practically all of the communities of the interior. The abuses to which these people were submitted was the cause for the strong anti-Roman sentiment throughout this nations. They kept their ancestral identification at the same time that they served the Romans.
Other leading cultural, administrative and economic centers of the Crown of Aragon, besides Zaragoza, were the cities of Barcelona and Valencia. Finally, Palma (Majorca) was an additional important city and seaport.
The Crown eventually included the Kingdom of Aragon, the Principality of Catalonia (12th century County of Barcelona), the Kingdom of Valencia, the Kingdom of Majorca, the Kingdom of Sicily, Malta, the Kingdom of Naples and the Kingdom of Sardinia. For brief periods it also controlled Montpellier, Provence, Corsica, and the twin Duchy of Athens and Neopatras in Latin Greece.
The countries that are today known as Spain and Portugal spent the Middle Ages after 722  (initial stage of the Islamic Conquest in the 710s and the Fall of Granada) in an intermittent struggle to expanding "Christian Kingdoms" in 1492. It ended immediately before the European landing to the New World which ushered the Era of the Portuguese and Spanish Colonial Empires.