Julian's Persian expedition

Julian's Persian expedition
Part of the Roman–Persian Wars

The body of Julian, killed in battle, is trampled on by King Shapur II in a relief from Taq-e-Bostan.
DateMarch–July 363 AD
Location
Result Sasanian victory
Territorial
changes
Sasanian annexation of five regions and fifteen major fortresses from the Roman Empire in addition to the consequent annexation of Armenia.
Belligerents
Roman Empire
Armenia
Sasanian Empire
Arab allies
Commanders and leaders
Emperor Julian 
Emperor Jovian
Arshak II
Hormizd
Arintheus
Victor (WIA)
Dagalaifus
Nevitta
Lucillianus
Procopius
Sebastianus
Shapur II
Ardashir II
Pigranes
Surena
Merena 
Nohodares 
Narseus
Podosaces
Mamersides
Strength

120,000 men

  • 95,000 Romans
  • 25,000 Armenians
1,150 ships
Unknown, but probably fewer
Casualties and losses
Heavy Moderate

Julian's Persian expedition took place from March to July 363 AD. It was the final military campaign to be undertaken by Roman emperor Julian, who died in battle at Samarra. The Roman Empire fought against the Sasanian Empire, which was ruled at the time by Shapur II, and sought to capture the Sasanian capital city Ctesiphon.

In order to mislead the enemy and to carry out a pincer attack, Julian sent a detachment to join with his ally Arshak II of Arsacid Armenia to take the Tigris route from the north. Meanwhile, his main army and a large fleet, facing little opposition, advanced rapidly down the Euphrates, destroying several well-fortified cities along the way. The ships then reached the walls of Ctesiphon, where a large Sasanian army had assembled in defensive positions.

The Romans won a victory outside the city, but the northern army failed to arrive, and the fortified capital seemed impregnable. Due to these complications, Julian did not attempt to besiege the city, instead burning the Roman fleet of supplies and leading a march into Persia. Shapur II's army, however, took lengths to avoid a full-scale battle and used a scorched-earth strategy, which eventually left Julian's army facing supply problems and forcing their retreat to the north. Shapur II's army pursued the retreating Romans, ceaselessly harassing the retreat through skirmishes. Julian died of wounds sustained from one of these skirmishes and was succeeded by Jovian, who agreed to surrender to the Sasanians under unfavourable terms in order to save the remnants of his demoralized and exhausted army from annihilation.

The Peace Treaty of 363 transferred multiple regions and frontier fortresses, including Nisibis and Singara, to the Sasanians. In addition to making territorial concessions, the Roman Empire renounced its alliance with Armenia, giving Shapur II the opportunity to invade and annex it.