People have lived in the area of Komárno for thousands of years. The first castle was built in the 10th century. In 1244 a law was made which said that every merchant who sailed a boat down the Danube past Komárno had to stop for several days in Komárno and unload all the cargo so that people could buy it if they wanted. If the merchant did not want to do this he had to pay a large duty (amount of money) to continue his journey. This law was stopped in 1751. 