Where does “Ксеркс” come from?

Ксеркс (Serbo-Croatian) comes from Ancient Greek Ξέρξης, from Old Persian 𐎧𐏁𐎹𐎠𐎼𐏁𐎠, from Old Persian *(w)r̥šā.

Ancestry of “Ксеркс”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	Ξέρξης	—
2	Old Persian	𐎧𐏁𐎹𐎠𐎼𐏁𐎠	ruler among kings
3	Old Persian	*(w)r̥šā	—