The walls were built systematically in the difficult times of permanent danger to the City and the Republic, and they have been preserved to the present day and are still functional, not only because of the proficiency of their skillful builders, diligence and care of the citizens of Dubrovnik who maintained them and added to them as necessary, but also because of the splendid ability of the famous diplomats who knew how to obviate and avert the dangerous intents of the enemies and rivals of the Republic.

The city of Dubrovnik is completely surrounded with walls and forts, including the Old Port. The history of the fortifications goes back to the early Middle Ages. No doubt the earliest urban settlement upon the islet of Laus was protected with walls. The fact that the city was able to resist the Saracens who besieged the city for 15months in the 9th century means that it was fortified well. The city first spread towards the uninhabited eastern part of the islet. The eastern section was included within the defence walls in the 9th and 10th century. When the sea channel separating the city from mainland was filled with earth in 11th century, the city merged with the settlement on land and soon a single wall was built around the area of the present-day city core. The whole city was enclosed in the 13th century, except for the Dominican monastery, which came under their protection not before the 14th century. The average thickness of the wall was 1.5 meters, and it was built of stone and lime. To increase the strength of the walls and ensure better defence, 15 square forts were built in the 14th century.