Who was the last emperor to have the FAMILY name of Caesar, who supplies the right answer, I will check best answer and i will supply the answer in a few days
I'm guessing Nero, his momma was Augustus' granddaughter.... right? But, I'm also guessing that one of them farther down the line might have snuck a distant family connection in there! Edit: looked it up, great-grandaughter.
Family name = Augustus? So... All of them & the last would be...(not gonna include Romulus Augustulus bc it's funnier to use the nickname) Julius Nepos in the West &, if we respect the commonly held "line" btw Roman/Byzantine (I know, I know, gotta stop somewhere though) then Anastasius (or Zeno if you prefer)?
It is time for the answer, Nero of the Julio-Claudian dynasty, he was the last emperor to have the family name of Caesar. He was the great, great grandson of Marc Antony and the great, great grandson of Caesar Augustus. The rest of the Julio-Claudian family was Tiberius, Caligula, Claudius, congrats to Norma Fries and Cherd
I lucked out. I am currently taking a 30 week ancient Roman history class and this very point was brought up. That Nero was the last if the Julio-Claudian family dynasty to become emperor.