In his first years he reigned under the regency of his mother Laodice, the eldest sister of the King Mithridates VI of Pontus.
During this period the kingdom was seized by King Nicomedes III of Bithynia, who married Nysa.
Nicomedes III was soon expelled by Mithridates VI, who restored upon the throne Ariarathes VII.
However, Ariarathes objected to Gordius, his father's assassin and ally of Mithridates VI, having a role in the government of Cappadocia.
Mithridates VI then put onto the Cappadocian throne his own 9 -year-old son, Ariarathes IX of Cappadocia, with Gordius as regent for the young king.