Farhad I, the eldest son of Frey Yapet Was . Although his younger brother - Mehrdad - had a great superiority over him in bravery and fighting .
But the assembly of Parthian elders - Mehstan - Due to Farhad's seniority, he considered only him worthy of his father's succession, anyway, he interfered his brother a lot in the work of the government. . Farhad I was able to conquer the current Mazandaran region, which until then was one of the Seleucid states, and annexed it to his country. .
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But the Seleucids, who were involved in western troubles, did not pay much attention to this issue, after that Farhad I succeeded in conquering Ray and Qazvin, where the Seleucids had very strong fortifications, such as Apamea Castle, near Dushan Tepe, and this indicates His power has been great . Farhad I died in 174 BC and ruled for 7 years from 181 to 174 BC. .
