Daniel 8:4 - Coke's Commentary on the Holy Bible

Pushing westward, and northward, and southward— Westward, that is, subduing Babylonia, Syria, and Asia Minor, under the reign of Cyrus, and extending to part of Greece under that of his successors, Darius the son of Hystaspes, and Xerxes. Northward; the same Darius, according to Herodotus and Justin, carried his arms into the territories of the Scythians, beyond the Caspian Sea; and the Lydians, Armenians, Cappadocians, Iberians, &c. were subject to Persia. Southward; the Persians extended their conquests over Arabia, India, Egypt, and Ethiopia, which last was entered by Cambyses the son and successor of Cyrus; and the Persian empire was very much enlarged and extended under the victorious arms of its first monarchs.