Livy was a Roman historian who was born in northern Italy about 59 BC, in the Late Republic, when Julius Caesar was just beginning his career. Livy moved to Rome and wrote his books during the reign of the first Roman emperor, Augustus. He wrote an account of the history of Rome from the beginning of the Republic in 509 BC to the reign of Augustus, in 142 books (we would call them chapters today).
Livy was especially interested in showing that people won when they were good, and lost when they were bad. Mainly, Livy shows Romans as good and their enemies as bad. For instance, he shows the Carthaginian general Hannibal as sneaky and savage, while Scipio, the Roman general, is honest and merciful. That's not because Hannibal was really bad and Scipio was really good; it's just what Livy wanted us to see, because he was a Roman like Scipio, and because he liked a story to have a good moral lesson. Probably both Scipio and Hannibal were good, strong leaders, or they wouldn't have been so successful.
Livy lived to be about eighty years old, and died during the reign of Augustus.