Nahavand — Fath al-Futuh

Nuʿman ibn Muqarrin al-Muzani ﵁, a veteran of Qadisiyyah and al-Madaʾin, was ordered by ʿUmar ﵁ to eliminate the last Sassanid fighting force in the mountains of western Iran. After the fall of Ctesiphon, Yazdegerd III had moved his court to the margins of the empire, and his general Pirozan had assembled a great gathering of Sassanid remnants and local allies in the mountain valley of Nahavand. It was the last organized counterforce of the collapsing empire.

Nuʿman ﵁ marched northeast from al-Qadisiyyah and Ctesiphon, along the old caravan routes that led through the Zagros mountains. His army numbered between thirty and forty thousand men. Among his officers were Hudhayfa ibn al-Yaman ﵁, Suwayd ibn Muqarrin ﵁ (his brother), and the descendants of al-Muthanna ibn Haritha.

The approach pass to Nahavand was narrow and heavily defended. Sassanid positions on the heights on both sides of the pass, the valley floor as deployment zone, and an eastern defile as the only exit toward Ctesiphon. Pirozan had deployed his main force in the valley, with reinforcements on the northern and eastern ridges, and with fortifications at the town of Nahavand itself at roughly the 34.19 parallel.

Nuʿman ﵁ called a halt about fifteen kilometers from the mouth of the pass. Scouts rode ahead and returned with sharp reports on Sassanid positions, observation posts, and the narrowest points of the pass. The pass was so tight that a direct assault was impossible without heavy losses. Nuʿman ﵁ conferred with Hudhayfa ﵁ and Suwayd ﵁ and chose a ruse maneuver that recalled Khalid ﵁'s method at Yarmuk.

At the evening salat the Sahabah ﵃ prayed behind Nuʿman ﵁. Afterwards he addressed them. “Tomorrow,” he said, “we shall feign flight, so that they come down from their hills, and we receive them on the plain where Allah ﷻ grants us the victory.”

On the second day Nuʿman ﵁ executed his ruse. He sent a Muslim vanguard into the pass, seemingly in a reconnaissance posture, and waited until Sassanid scouts reported their position to Pirozan. When Pirozan responded by sending cavalry down from the hills to cut off the Muslim vanguard, Nuʿman ﵁ gave the order for an orchestrated withdrawal.

The Muslim vanguard fell back in apparent panic, with banners streaming backwards and ranks that seemed to be falling apart. It was, just as at Yarmuk, a choreography. The withdrawal moved toward the western mouth of the pass, where Nuʿman ﵁'s main force and Muslim archers waited in hidden positions behind the rocks.

Pirozan saw the flight and committed. He sent his main cavalry down the hills, convinced that the Muslim force was in full rout. The Sassanid horsemen rode in swift pursuit, and the Sassanid infantry on the hills likewise began to descend to join the chase. A substantial part of the Sassanid force thereby abandoned its fortified positions on the heights.

Muslim archers loosed aimed volleys at the descending Sassanids from hidden positions. The Muslim vanguard sustained its “flight,” drawing Pirozan ever deeper onto the valley floor. By mid-afternoon the great majority of the Sassanid force was in the open valley below, and their fortified positions on the northern and eastern ridges stood largely vacated.

Nuʿman ﵁, from his observation post on the southern edge of the pass, watched the picture unfold exactly as he had foreseen. He gave the signal to his hidden reserves.

When the Sassanid pursuit had been drawn deep onto the valley floor, Nuʿman ﵁ gave the signal for the hidden reserves. From the northern and eastern ridges, and from the tree line at the valley’s edge, Muslim units emerged simultaneously. The pass at the Sassanids’ rear, which they had abandoned in the pursuit, was sealed by a Muslim occupying force.

The encirclement was complete in less than an hour. Four or five Muslim reserves appeared at the four cardinal directions, and the Sassanid force — scattered earlier by the pursuit — found itself surrounded on the open valley floor. Pirozan tried to organize a rally on a raised position at the center of the valley, and sent couriers to his officers to bring the main force back into formation.

The rally partly succeeded. The Sassanid heavy cavalry and the elite units under Pirozan’s direct command formed into a great circle formation in the heart of the valley. The lighter cavalry and infantry, who had become most scattered in the pursuit, could no longer link up and fell into loose fighting with the Muslim units surrounding them.

Nuʿman ﵁ sent Hudhayfa ﵁ with a light cavalry group to seal off the northern exit of the valley completely. Suwayd ﵁ was ordered to bring the eastern pass exit toward Ctesiphon under control. With that, every Sassanid escape route, in whatever direction, was closed.

Pirozan looked out from his rally position at the Muslim units strengthening around him. He knew that the last fortified Sassanid army was trapped in the valley. He sent one final courier to Yazdegerd III with a request to bring reserve troops down from the north, though he knew such a courier would most likely not even make it through the pass.

On the third day of the engagement Nuʿman ﵁ committed the main infantry to a frontal assault on Pirozan’s rally formation. Muslim archers loosed long volleys at the Sassanid center units from prepared firing positions, and Muslim heavy infantry marched in compact ranks toward the Sassanid circle formation.

The Sassanid circle formation received the Muslim assault with its customary discipline. Heavy cavalry on the outside, light cavalry and archers directly behind, infantry at the heart as reserve. The first Muslim charges were repelled, particularly on the northern side where the Sassanid bodyguard was strongest.

But Nuʿman ﵁ had kept the Muslim cavalry reserves back on the flanks. He sent a simultaneous charge of Muslim horsemen against the left and right edges of Pirozan’s formation. The flanking cavalry worked inward from the hillside, with speed and momentum on their side, and broke through the outer cavalry ring on both sides almost at the same moment.

Pirozan responded with a desperate counterattack. His elite cavalry, some one thousand horsemen, came forward in a focused thrust against the Muslim center. It was an attempt to reach Nuʿman ﵁'s command position itself and decide the battle at the top. The thrust drove a few hundred meters into the Muslim line, but was beaten back by Muslim heavy infantry before it reached the command post.

By late afternoon the Sassanid circle formation had been broken in several places. The outer cavalry was exhausted; the center units began to waver under relentless archer pressure. Pirozan himself rode from point to point to hold his units in line, but the gradual dissolution could no longer be stopped.

Toward evening on the third day the Sassanid right flank finally gave way. But before the victory could be claimed, Nuʿman ibn Muqarrin ﵁ himself fell. The sources differ on the precise circumstances, but the main line is the same. Nuʿman ﵁ rode to the front line in the afternoon to direct a final push, and was struck by a Sassanid arrow or a well-aimed spear. Some traditions place it during a Muslim charge against the Sassanid bodyguard; others relate that he fell from his horse under a general Sassanid volley.

On the battlefield his banner, with the embroidered colors of his tribe, became visible to the men behind him. Hudhayfa ibn al-Yaman ﵁, who rode beside him, called the commanders together and covered his body with a cloak. Under strict orders the news was not spread until later that evening, so that the Muslim force would not falter in its final push. Hudhayfa ﵁ immediately assumed the supreme command, and gave the signal for the final charge against the Sassanid right flank.

Nuʿman ﵁'s last words, according to the tradition, were a prayer for his men and a question whether the battle had yet been won. Hudhayfa ﵁ told him that Pirozan was in flight, and Nuʿman ﵁ passed away with a smile on his face. A man who had fought with the Prophet ﷺ at Khaybar, who had served as a core commander at al-Qadisiyyah, and who on this day had won fath al-futuh in the name of Allah ﷻ.

At almost the same hour Pirozan fell. With his right flank in full dissolution, he attempted a fighting retreat toward the eastern defile. A Muslim cavalry commander — the sources name ʿAmmar ibn Yasir ﵁ in some traditions, in others a lesser-known Sahabi — managed to overtake Pirozan a few hundred meters from the defile. Pirozan was mortally wounded, and his body fell beside his horse on the dusty valley floor.

With the death of Pirozan the Sassanid morale broke. His elite bodyguard laid down their arms or was cut down in one-sided fighting. The Sassanid right flank, and soon the center as well, broke apart in a general rout eastward, toward the narrow defile that led to Ctesiphon.

Under Hudhayfa ibn al-Yaman ﵁'s command the Muslim force launched the final pursuit. The fleeing Sassanid remnants streamed en masse through the narrow eastern defile in the direction of Ctesiphon. But the defile was too narrow for so great a mass, and the mountain slopes on both sides offered no escape route.

What happened in the defile is described in the traditions as a slaughter in a funnel. Muslim cavalry closed in behind the Sassanid remnants and barred their way back; Muslim archers occupied the mountain slopes on both sides and loosed aimed volleys downward. The Sassanids, packed together in the narrow passage, could scarcely use their weapons and had no room to fight in formation. Thousands fell.

The survivors who finally reached the eastern exit of the defile — a few thousand exhausted cavalry riders — fled in disorder toward Ctesiphon and, beyond it, the Iranian highlands. Yazdegerd III, when the news reached him in a distant garrison town, set off for the far northeast. He would live another ten years in the margins of the collapsing empire, before being murdered by his own servant in a flour mill in Merv in 31 AH.

Hudhayfa ﵁ consolidated Muslim control at Nahavand. The garrison was established in the town itself, the fortified Sassanid position was taken over, and the khums was divided in the Muslim manner and sent to Medina. On the spot where Nuʿman ﵁ had fallen a simple grave was raised; his body was buried there without ghusl, with his blood and his weapons, for he was shahid.

When the news of the victory reached Medina, ʿUmar ibn al-Khattab ﵁ called the people to the salat and addressed them from the minbar. “The Sassanids will never again rise against us in unity,” he said. He devoted long duʿa to Allah ﷻ for the victory. In history the victory received the name fath al-futuh, the opening of openings, for it broke the last central state power that could still resist the Muslim conquests in the east. With Nahavand the Sassanid empire was de facto dismantled, and the work begun under ʿUmar ﵁ could be completed under his successors.