The "Year of the Four Emperors" refers to the year 69 AD in the Roman Empire, marked by a rapid succession of rulers following the death of Emperor Nero. This period was characterized by political instability and civil war, as four different leaders claimed the throne: Galba, Otho, Vitellius, and Vespasian. Each emperor faced challenges to their authority, leading to conflicts and shifting allegiances among the military and political elite. Ultimately, Vespasian emerged victorious, establishing the Flavian dynasty and bringing a degree of stability to the empire after the chaos of 69 AD.