This is the starting year to the modern calender that labels all additional years as "Common Years" or CY for short. The Common Year was established as the system of reckoning by Grand Prince Nasran I of the Great Kingdom of Aerdy in 645 OR (1 CY), when he declared universal peace throughout his land and took the title of Overking. While the universal peace did not withstand, the new calendar was adopted by most of Greyhawk.