How do our sources about the life of Jesus compare to our sources about other ancient figures? Michael Licona (Ph.D. in New Testament Studies from the University of Pretoria) explains that the evidence for Jesus is quite good. Other prominent figures in the ancient world, such as Caesar Augustus, aren't even as good as what we have for Jesus.
Caesar Augustus is regarded as Rome’s greatest emperor and was ruling the empire when Jesus was born. Historians rely on six chief sources to learn about Augustus’s adulthood: a funerary inscription that is nearly 4,000 words in length, Plutarch who wrote around 90 years after Augustus’s death, and four others writing 100-200 years after his death. When we consider that this is what we have for the greatest Roman emperor, four biographies of Jesus written within 35-65 years of His death is pretty good!
Paul Copan and William Lane Craig, eds., Come Let Us Reason: New Essays in Christian Apologetics (Nashville, Tenn: B & H Academic, 2012), 143.