The Tosfot in Chagiga makes an interesting observation regarding our exile and the suffering that the Jewish people have had to endure over the generations. Hashem's love for His people is so strong that even when He punishes us, He wants us to have our dignity. For this reason, Tosfot says, the messengers chosen to carry out this punishment, are first elevated to high positions before they unknowingly fulfill their mission. It would be a disgrace for the Jews to fall at the hands of some insignificant anonymous oppressor. Instead He chooses a viceroy to the king like Haman to torture the Jews. Or He might take a Roman Caesar to afflict the Jews. This was true of Sancheiriv of Assyria and Nebuchadnezzar. These were leaders of great prestige to still give honor to the Jews. This also made their demise more significant because time after time, those that even attempted to harm the Jews, were brought down in great humility.