Well, I find character lists useful for Historical fiction when you have:
Julia Drusilla
Julia Livilla
Julia Agrippina
Julia the Elder
Julia Flavia
Agrippina the Elder
Drusus, Drusus and Nero and Nero.
Gaius, Gaius and also Gaius. All different generations, I might add.
Titus Flavius Sabinus, but also Titus Flavius Sabinus, his son.
Also when in the middle of the story when Lucius Domitius Ahenobarbus changes his name to another long name, but he just goes by Nero.
Yeah. These are all real people and in the same family tree, except Julia Flavia. It's a mess!