MCDLXVI is the Roman numeral representation of the number 1466. In this system, "M" stands for 1000, "CD" represents 400 (500 minus 100), "LX" signifies 60 (50 plus 10), and "VI" means 6. When combined, these values total 1466. The year 1466 is notable in history for various events, including the signing of the Treaty of Thorn, which ended the Thirteen Years' War between the Teutonic Order and the Kingdom of Poland. This treaty marked a significant shift in power in the region, leading to the establishment of the Duchy of Prussia.