Middle Ages and the Christian Kingdoms
The western Roman Empire, with the population contribution from peoples of Germanic origin, gradually changed over time until it was replaced as a political entity by a mosaic of Germanic kingdoms, with a greater or lesser degree of Romanisation. The Byzantine Empire continued the Roman tradition throughout the Middle Ages.
From the 8th century onwards, and for almost eight hundred years, the western frontier between the Christian and Islamic worlds lay in the Iberian Peninsula. Islam had recently produced its own coinage that drew on the gold Byzantine coins and silver Neo-Persian coins. The most notable feature of these coins was that they bore no images.
The Islamic states on the Peninsula minted gold coins (dinar), silver coins (dirham) and copper coins (fals). In the 11th century the Muslim area, which during the emirate and caliphate had constituted a single Arab state, broke up into several smaller regions known as taifas.
This is when the Almoravids arrived, who were later overthrown, in all their areas of influence, by the Almohads. The Almoravids issued a prestigious gold dinar and a silver coin called a qirat. The Almohads made heavier dinars than the Almoravids, which the Christians called doblas, and a silver square-shaped dirham.
The Christian Kingdoms
Christian coins returned to iconographic representations, but giving considerable importance to mottoes or inscriptions. Coins once again bore portraits of governors as a symbol of the issuing authority, but we also see other types of symbols of this power, such as crosses, monograms or heraldry. By the late 11th century all Christian states on the Peninsula were issuing their own coins.