Late Middle Ages
The “Repubbliche Marinare” (Maritime republics) of Amalfi, Gaeta, Venice, Genoa, Ancona, Pisa and Ragusa developed their own empires in the Mediterranean shores. The Islamic states had never been major naval powers, and trade from the east to Europe was soon in the hands of Italian traders, especially the Genoese and the Venetians, who profited immensely from it. The Republic of Pisa and later the Republic of Ragusa used diplomacy to further trade and maintained a libertarian approach in civil matters to further sentiment in its inhabitants.
The Republic of Venice got to dominate the eastern Mediterranean shores after the Fourth Crusade.
Between 1275 and 1344 a struggle for the control of the Strait of Gibraltar took place. Featuring the Marinid Sultanate, the Nasrid Kingdom of Granada, the Crown of Castile, the Crown of Aragón, the Kingdom of Portugal, and the Republic of Genoa, it was characterized by changing alliances between the main actors. The iberian cities of Tarifa, Ceuta, Algeciras or Ronda and the African port of Ceuta were at stake. The Western Mediterranean sea was dominated by the Crown of Aragon: thanks to their possessions of Sicily, the Kingdom of Naples, the Kingdom of Sardinia, the Balearic Islands, the Duchy of Athens the Duchy of Neopatria, and several northern African cities.
In 1347 the Black Death spread from Constantinople across the Mediterranean basin.
Ottoman power continued to grow, and in 1453, the Byzantine Empire was extinguished with the fall of Constantinople. The Ottomans already controlled Greece, Bulgaria and much of the Balkans and soon also began to spread through North Africa. North Africa had grown wealthy from the trade across the Sahara Desert, but the Portuguese, who, along with other Christian powers, had been engaged in a long campaign to evict the Muslims from Iberia, had found a method to circumvent this trade by trading directly with West Africa. This was enabled by a new type of ship, the caravel, that made a trade in the rough Atlantic waters profitable for the first time. The reduction in the Saharan trade weakened North Africa and made them an easy target for the Ottomans.
Ceuta was ultimately taken by the Kingdom of Portugal in 1415, searching to undermine Castilian, Aragonese, and Genoese interests in the area.
During the Middle Ages, rival Christian and Muslim kingdoms forbade the trade of particular goods to enemy kingdoms including weaponry and other contraband items. The popes forbade the export of these commodities to the Islamic world. The Ottomans too forbade the export of weapons and other strategic items, declaring them memnu eşya or memnu olan to Christian states even in peace treaties, however, friendly states could import some of the prohibited goods through capitulations. Despite these prohibitions, trade of contraband occurred on both sides. The European merchants traded illegal goods with Muslims. The Ottomans were unable to suppress the trade with smuggling being undertaken mainly in the winter when the Ottoman Navy stationed at the Istanbul Arsenal was unable to stop Ottoman and non-Ottoman vessels from indulging in the trade.