[Caesar] could number the whole world Luke 2:1
Actually, "inhabited earth" or "world" (οἰκουμένην) in Luke 2:1 is usually understood to refer to the Roman Empire (see here). A sizable area for sure, but definitely not the entire earth. And Rome had a few other rival empires to contend with over time such as the Carthaginians and the Parthians. (See here.)