Battle of the Persian Border The Battle of the Persian Border was the second encounter between the forces of Media and Persia . Though not a decisive victory for Persia , it signaled the diminishing power of Media in Southwest Asia . It was the first battle Cambyses I had fought in , and the first which he had fought with his son , Cyrus the Great . The first major battle , which lasted two days , was an attempt to bring freedom to Persia . It also prompted the Persians to retire south , and fight a third battle . It was narrated by Nicolaus of Damascus , and among others who also mentioned the Battle of Hyrba , but Herodotus does not mention this battle . Most historians on the battle consider Herodotus to be mentioning only the first and last battles in the war , which is partly based on the description of his two battles . At the border this became the first major battle between the two powers . Cyrus managed to escape the enemy without retreating , thus ending the battle and prolonging the struggle without a complete victory for Astyages , the king of the Medes . The next battle became the last stand for the Persians ; as their very existence relied on the outcome of the war , which had to be won . Background . Cyrus had retired to the border of the Median province to protect the Persian border against Astyages . After the Battle of Hyrba Astyages invaded Persia with 1 , 205 , 000 + men . The battle that was to come was composed of cavalry from both sides , and chariot s that in most part were used for the battle , for they were never used again . A small part of the invasion force from the Medes participated in the battle , while the Persians spent all their cavalry from their reserves . Astyages had tried to persuade Cyrus to surrender but he now preferred to show no mercy even though he had better relations with Atradates ( the variant name of Herodotus ' Mitradates , which Nicolaus mistakenly uses for Cambyses , the father of Cyrus ) . The name of the city Cyrus and his father were protecting was not given . Nevertheless the city was an important frontier town worth the protection . When Astyages came within reach of the city , Persian civilians were ready to evacuate if necessary . Meanwhile , Cyrus and Cambyses assembled the army , but it is not exactly known whether Oebares ( who helped Cyrus to the throne ) or Harpagus participated on the side of Cyrus in the battle , it is known that the original Oebares was an advisor to Cyrus . So Nicolaus , as he is known to change names around , may most likely be saying Harpagus was in the battle , as he was historically Cyrus ' s second in command and the only other choice available , but in this battle it seems Oebares was on Cyrus ' side . Then it could also be said as Herodotus mentions , Harpagus was the most likely candidate that was in this battle that occurred about a year after the first battle . Therefore , as battle began , Astyages had his special troop s positioned to attack at the rear . Aftermath . After the first days battle the Persians had either inflicted massive casualties on Astyages ' personal guard that was made up of cavalry , or the rest of his army that was also cavalry . Nevertheless , the Persians still claimed victory the first day . The second day of the battle Cyrus , assuming the battle had ended , secretly retired south with the rest of the armed forces , while only Cambyses and a few old men remained in the city . When Cyrus was forced to fight again , Astyages ' ingenious move of cavalry occurred , which was aimed at capturing the poorly guarded city . As he was assuming the battle had not ended , he easily captured the city , while only Cambyses is reported to have been wounded and later died . It is debated among today ' s historians if the second day is to be counted as part of the original battle , or that it should be counted as a separate battle . As the Persians retired south , Astyages readily abandoned the city , which is based partly on the scant sources from Nicolaus , therefore not becoming a complete victory for Astyages , as he is not known to put a garrison there after he and his forces went south after the Persians . It was however a psychological blow to the Medes as they thought the Persians were lucky in the first battle , but again the Persians won , this time tactical ly . Both armies later went back to their camps and organized their armies while deciding where to meet for the next fight . Then as the year passed , both forces agreed to meet at the Persian capital which Astyages wished to capture .