After the death of Vagharsh II, his son
Khosrov I the Brave (206–253) was proclaimed king of the Kingdom of Greater Armenia. He was a man of great intellect, exceptional organizational talent, as well as notable military and diplomatic abilities. At the beginning of his reign, he crossed the
Caucasus Mountains, and as a result, in the spring of 207, the army of the Kingdom of Greater Armenia (approximately 110,000 troops), led by Khosrov I the Brave, sparapet
Ashot Bagratuni, and Babken Artsruni, passed through the Derbent Pass on a punitive campaign and defeated the combined forces of the Basilian and Alanian kingdoms (around 60,000 troops, including Sarmatians, Khazars, and Bulgars) in the Battle of
Derbent Fortress. As a result, the war initiated earlier by his father, Vagharsh II, came to an end.Consequently, the kingdoms of
Alania, Basileia, and Caucasian Albania recognized the supremacy of the Kingdom of Greater Armenia, while hostages were taken from the
Sarmatians,
Khazars, Basilians, and Bulgars as guarantees of the concluded peace. The borders of Armenian dominance extended northward to the southern valley of the Volga River and the Ciscaucasian steppes, and eastward to the
Caspian Sea and
Atropatene. Thus, succeeding his father and inflicting a crushing defeat upon the combined Basilian and Alanian forces, Khosrov I the Brave—who already held the Kingdom of Iberia under his authority through his brother Rev—also imposed allied obligations upon the Basilian and Alanian kingdoms, effectively creating a powerful confederation of northern states under the supremacy of Greater Armenia. While protecting the interests of the priestly class, he persecuted Christian communities.In 202, together with his ally, the Roman Emperor Septimius Severus, he was present in Egypt during the latter’s campaign.Following the Sasanian coup against the Parthian Arsacids in 208–209, and in 213, Khosrov I allied himself with and supported Artabanus V, who had been proclaimed King of Kings in Parthia in opposition to Vagharsh VI.In the autumn of 216, Khosrov I the Brave, together with his wife, arrived at a Roman imperial camp located in
Corduene, where, however, the Armenian king and queen were captured. Upon learning of this, the army of Greater Armenia (about 100,000 troops), led by Prince Trdat, set out on a campaign and advanced toward the enemy. In response, the Roman army under Theocritus also moved to meet the Armenian forces. The armies approached each other and formed battle lines. The Armenian army inflicted a heavy defeat on the Roman forces, which retreated toward Edessa. Meanwhile, the Roman army (approximately 140,000 troops), led by Septimius Caracalla, marched along the route
Edessa–Carrhae–Nisibis–Arbela and prepared to invade the territory of the Parthian kingdom. Upon learning this, the combined forces of the Parthian kingdom (around 80,000 troops), led by Artabanus V, and the Kingdom of Greater Armenia (around 100,000 troops), led by Prince Trdat, advanced toward the enemy, which retreated as far as Nisibis and encamped nearby. However, on April 8, Caracalla was assassinated by his own guards. Thereafter, in the immediate vicinity of the opposing army, his secretary and the true organizer of the conspiracy, Marcus Macrinus (217–218), was proclaimed emperor. Under these circumstances, on April 9, the opposing sides approached each other and formed battle lines. On that day, the combined Parthian and Armenian forces launched an attack, but the fierce battle, which lasted all day, brought no advantage to either side. On April 10, the engagements continued with no decisive outcome. On April 11, the allied Parthian and Armenian army, superior particularly in cavalry, launched another attack and attempted to outflank the Roman formation; in response, however, the Romans extended their lines and managed to hold their positions. As a result, the intense and bloody fighting that continued throughout the day again produced no decisive advantage, and by the end of the day, both sides—having suffered heavy losses—retreated to their initial positions. In these difficult circumstances, Marcus Macrinus, fully understanding that his equally strained opponent was fighting stubbornly, likely driven by a desire for revenge against Caracalla, released Khosrov I the Brave and his wife on April 12. Through them, he informed the opposing command that Caracalla had been dead for four days and, taking this into account, proposed concluding peace. The proposal was accepted, and thus peace was concluded, bringing the Fifth Roman–Parthian War to an end. As a result, Khosrov I the Brave was restored to the throne of Greater Armenia. The age of the Arsacids was coming to an end, and the era of the Sasanians was beginning. == The outbreak of the Arsacid War ==