How the Islamic civilization emerged in the Balkan Peninsula is one of the most complex problems and requires multi-dimensional research. Unfortunately, many historic facts concerning Islam and the Balkan Peninsula have been "forgotten," or even distorted. This has been the result of centuries of pressure from the Serb and European historians and their political establishments.
The two ways that enabled the spread of Islam in the Balkans were:
(1) The military expeditions sent to extend the borders of the state of Islam, and
(2) The persuasive powers of the Islamic teachings themselves made people ultimately embrace it.
Insofar as the nations of the Balkan Peninsula are concerned, the overwhelming historic evidence reveals that military expeditions were of little significance in the spread of Islam. Thus, the teachings of Islam were the crucial factor in winning people over. The Quranic declaration that "there is no compulsion in religion," gave people the feeling of freedom for the first time in centuries. The very famous Albanian writer, S. Frashëri, observes: "Apart from the usage of military might to spread Islam, there does exist another way without turning to invasion or the force of arms, a way that is often not mentioned by the historians." Arnold Toynbee considers this a major point and mentions it in his book, too.
Looking back in history, it is easy to understand which way was the most influential means of spreading Islam; the force of arms or Islamic teachings. Most of the time, the Muslim armies only opened the "door" for the Islamic civilization to present itself, and ultimately the people would see the difference.
Islamic civilization entered the Balkan Peninsula mainly from the West through the contacts with Andalusia in Spain, from the South through Mediterranean Sea and Sicily, and from the Northeast through Hungary. Even though the evidence is minimal, after a serious analysis, the above question—how did Islam come to the Balkan Peninsula—would be finally answered.
After all the research, three are the ways through which the Islamic civilization gained its foothold in the Balkan Peninsula, and a further elaboration of them will follow.
The development of Islamic civilization and of the Muslims themselves conditioned the expansion of trade. The goods produced were mainly traded with neighboring nations, however, the traders often ventured even further to far and unknown places. This is why that since the 9th century trade relations between Europe and the Middle East through the Mediterranean Sea has been booming. In these trade relations, the most daring Europeans were those from Florence, Venice, Pizza, Genoa, followed by the French, and Catalonians. The European merchants through Egypt and Syria ventured far into the Far East.
The Illyro-Albanians had established trade relations with the Arab and Turkish nations, and not only the port-cities of the Adriatic Sea, but the rural parts of the Balkan Peninsula inhabited by them as well. Such strong trade relations had been established since ancient times, and continued into the pre-Ottoman and Ottoman periods.
The Arab gold and silver coins excavated in Potoci, near Mostar of the present-day Bosnia-Herzegovina, date back to the time of Marwaan II (744-750 C) which tells of the extensive trade relations the Muslims had with the Balkan nations, first the Albanians and later the Slavs.
Port-cities along the Adriatic Sea like Dubrovnik, Tivari, Ulqini, Durazzo, Valona, Himara, etc., and other Greek and Southern Italian cities were centers of trade. During the 12th century, the well known Muslim historians and travelers, Al-Idreesi and Ibn Hawkal, tell in fine details the social and political situation of those places. They also describe the road going through the Balkan Peninsula, from the Aegean Sea along the valley of the Vardar River to the coasts of the Adriatic Sea.
Usually, the Italian merchants traveled by sea, whereas the Muslims mostly traveled overland. The merchants from Venice and Florence used to trade regularly and exchanged their goods mostly in Istanbul and Gallata. Well known are also the caravans from Dubrovnik to Istanbul, and vice versa.
Such strong trade relations have had a great impact on the Balkan nations. Apart from buying and selling, which was the primary intention, the merchants brought many new ideas and changes. This was intensified further when the Muslim merchants started to establish themselves in some fortified and secured coastal cities. The first Muslim colonies appeared. Though they were very small in the beginning, they became larger, and even stronger.