I. Leo was born in 401. Leo's full name is Flavius Valerius Leo. Leo became emperor of the Eastern Roman state in 457.
Leo tried to strengthen the eastern Roman empire. Leo especially tried to create a very large army. In addition, Leo has been involved in the internal affairs of Western Rome. Leo wanted to choose the emperors of Western Rome himself. Because of this request, many revolts began in the Western Roman empire.
Leo has finished all the revolts against him. Leo wanted to conquer Carthage, which was in the hands of the Vandals. So Leo started a war against Vandals. But the Roman army lost this battle, even though they have more soldiers. And 30,000 people from the Roman army were killed.
But the people of East Rome have always supported Leo despite his defeat. Leo died in 474 due to dysentery.