Xerxes is mentioned in the Bible in the Books of Esther and Ezra
The most famous Xenophon is a Greek historian, soldier, mercenary and philosopher, a contemporary of Socrates and Plato
Some people pronounce the X in Xavier; others say it like a Z
Xanthos is the name one of the twelve sons of the Greek god Pan, and various other mythological folks and creatures
Xander is generally pronounced “zander”