Quote:Another good analogue would be the name of Caesar, being just a surname originally. However starting with Augustus, one of the titles of the Emperor of Rome was Caesar.
"Caesar" was the cognomen of that particular branch of the Julian family - and its meaning is obscure - but the first five emperors were all adopted into the family, It was not until the short-lived Emperor Galba that a non Julio-Claudian usurped the name Caesar and even he took "Caesar Augustus" as an addition.
Similarly Otho who followed but Vitellius added "Germanicus Augustus" to his name for his short reign before Vespasian showed up and reverted to the addition of "Caesar Augustus" to his own Titus Flavius Vespasianus. So this sort of thing did not manifest itself in a single generation.