מדרש על דברי הימים ב 36:23

The seventh king was Cyrus, who ruled from one end of the world to the other, as it is said, "Thus saith Cyrus king of Persia, All the kingdoms of the earth hath the Lord, the God of heaven, given me" (2 Chron. 36:23). Ahasuerus ruled over half the world. Is not half the world but 116 provinces, as it is said, "This is Ahasuerus, who reigned from India unto Ethiopia" (Esth. 1:1).