Armenia was never conquered by Alexander the Great. The Cambridge University historian W. Tran in his fine work on Alexander’s conquests noted:
“Alexander the Great appointed Mithrinés as the satrap of Armenia and sent him there, but the country was never conquered.”
Later he continued:
“The successors of Alexander came quickly to the conclusion that it was wiser to give up any hope of having a satrap in Armenia, since the country already had become independent and was ruled by a dynasty founded by Orontés.”
The Roman historian Pompeius Trogus (recounted by Marcus Junianius) confirms as he mentions that: “Neither Alexander, who subdued all Asia, nor any of his successors or posterity had been able to meddle with the people of Greater and Lesser Armenia”.
W. Tarn, The Heritage of Alexander, Cambridge Ancient History, vol. VI, p. 464
W. Tarn, Alexander, The Conquest of persia, Cambridge Ancient History, vol. VI, p. 83
Justin, Epitoma Historiarum Philippicarum Pompei Trogi, xxxviii. 7