It was the fourteenth year of the Zhenguan reign of the Great Tang, the ninth year of the Persian calendar of Yazdegerd, and the thirty-fifth year of the reign of Harsha, King of Tianzhu.

The eastern mountain regions of the Sasanian Persian Empire, the province of Khorasan. Late at night at the end of summer. Heavy rain.

A violent rainstorm swept across the mountain ranges and the battlefield. A terrible battle between the Persian Empire and the Arabs had just come to an end. Throughout the valley lay the bodies of the fallen, broken spears, bent swords, and shattered leather shields. Battle flags that had been cut down were rolled into the mud. Dead warhorses and war elephants bristled with arrows, and the bodies of warriors were largely incomplete — severed limbs and solitary heads scattered throughout every corner of the battlefield. Rainwater mixed with fresh blood carved gullies across the ground.

On the battlefield, a group of white-clad Nasas were gathering the corpses. They wrapped the bodies in white hemp cloth, two men to a body, and carried them up a mountain peak. The Nasas moved like ants transporting loads, forming a long procession along the mountain path. The mountain rain made the path slippery, and many Nasas fell and tumbled down the slope and off the cliff’s edge — yet no one said a word. Those who came after picked up the bodies the fallen had been carrying and moved silently forward.

They knew that Yazdegerd III, Emperor of Persia, was waiting for them on the mountain. More precisely, the Emperor was waiting for the bodies of these brave warriors, intending to bury them in the Tower of Silence with the grandest of ceremonies, so that they might return to the embrace of Ahura Mazda, the deity of the Zoroastrian faith.

The Nasas carried the bodies to the summit of the mountain, where Yazdegerd III stood by the roadside awaiting them. The rain had drenched him through and through; his gaze was vacant, and on his face one could not distinguish rain from tears. An attendant moved to raise a canopy over him, but Yazdegerd III pushed it away. As he watched the bodies of the warriors being brought up, Yazdegerd III said in a hoarse voice: “Dress me in the royal robes and the Sudre. I will receive them.”

The attendants dressed him in a golden silk robe, drew over it a white Sudre, fastened around him a sacred Kusti woven from seventy-two strands of white ox-tail hair, placed the imperial crown upon his head, and handed him a scepter cast from gold. Yazdegerd gripped the scepter and performed the ceremonial salute, watching calmly as the Nasas carried the remains past him and toward the heights of the mountain range. There, five sacred fire altars stood tall, the sacred fires burning fiercely upon them. Five sacred fires: the Fire of Sassan, the Fire of Priests, the Fire of Victors, the Fire of Warriors, and the Fire of Yazdegerd. The first four sacred fires had burned for four hundred years without ever being extinguished, symbolizing respectively the fortunes of Sasanian Persia’s state, the fortunes of the Zoroastrian faith, the martial fortunes of the Sasanian military, and the destiny of the soldiers. The last fire symbolized the personal destiny of Yazdegerd III himself, and had burned for only nine years.

In the heavy rain, the Dastur and the faithful kept adding wood and oil without cease to maintain the fires’ burning. For these were the last sacred fires of the Sasanian Persian Empire and the Zoroastrian faith. Four years earlier, Yazdegerd III had abandoned the imperial capital under the Arab onslaught and fled to the empire’s eastern borderlands. The Arabs had nearly destroyed all of the Zoroastrian altars and sacred fires. Over these four years, he had led the Persian royal family and the subjects who followed him in fighting and fleeing, driven steadily eastward by the Arabs; the sacred fires they carried had been lost almost entirely.

At the mountaintop, the Persians had already built a Tower of Silence. This tower was immense, constructed of stone, circular and roofless. Inside was a circular platform paved with dressed stone, fitted together precisely so that no corpse might contaminate the earth. The platform was divided into three rings, each ring marked out with squares of pigment to hold the bodies. According to Zoroastrian teaching, the outer ring was for male bodies, the middle ring for female bodies, and the inner ring for the bodies of children. Walkways were left between the rings and between each body’s space, so that the Nasas might carry the bodies through.

At this point, the Nasas had arranged the bodies according to sex and age. In a short time, bodies thick as a field covered the Tower of Silence, piled up like mountains. Some bodies were still draining blood, which in the rain’s wash flowed through the channels down to the central position of the innermost ring — a deep well whose bottom and walls were paved with stone slabs, its bottom connected to four drainage ditches, at the ends of which were placed charcoal and sand and gravel. In ordinary times, after the bodies had been long exposed to sun and the picking of vultures, the fine bone fragments and bodily fluids would be filtered here; but now what flowed through was fresh blood. After the first layer of filtration, the rainwater became somewhat clearer, then flowed into an underground well whose bottom was lined with a thick layer of sand. There, the last trace of the bloody water was filtered away and became pure rainwater, entering the rivers and the earth.

This was the Zoroastrian believers’ final resting place — not polluting a single inch of earth with their own bodies.

Having labored through the whole of one night, the Nasas had transported all the bodies into the Tower of Silence. By this time it was already morning; the rain continued to fall, and the mist in the mountains lay vast and gray. Yazdegerd III led the Persian royal family and the Dasturs in a ceremony of sacrifice. The Dasturs sang the ancient Zoroastrian liturgy, while Yazdegerd III unbound the sacred Kusti and raised it in both hands, swaying it gently.

We praise the souls of the righteous faithful — pure, good, and mighty. They are the most agile riders, the most astute leaders, the most steadfast supporters, the most irresistible of weapons.

When Spenta Mainyu raised the heavens, created the earth, the cattle, the rivers, and the plants, protecting the child within the womb, sustaining its life, and at birth uniting its flesh and bones, hair and limbs, organs and vital parts and reproductive organs, Mazda called upon the souls to come and help protect the heavens, the earth, the rivers, and the plants.

We praise the souls of the righteous faithful — pure, good, and mighty. Extraordinarily valiant, they struck their enemies with force from the heights; on the field of battle they severed and brought to the ground the strong arms of their wicked foes.

We praise the souls of the righteous faithful — pure, good, and mighty. They formed numberless armies clad in sturdy armor and bearing sharp weapons, raising aloft shining banners.

At this moment, a dull sound rumbled through the valley — a unit of Persian heavy cavalry came galloping to the foot of the mountain. The general at the head, helped by his attendants, removed his armor, breastplate, helmet, arm guards, and other equipment before he was able to leap from his horse, and then climbed the mountain almost on all fours. The atmosphere on the mountain instantly grew tense.

Yazdegerd III watched silently, his face pale with anxiety.

The Grand Dastur said in a low voice: “Your Majesty, it is General Firuz. The Arabs are likely about to attack again. You and the royal family should depart first! A few hundred li beyond these mountains lies the Indus River. This land of five rivers, with its crisscrossing waterways, is something that Arabs raised in the desert simply cannot cross. Our Sasanian Persia will be able to preserve its last sacred fire.”

Yazdegerd III gripped the scepter tightly, his five fingers pale: “If I have no subjects and no army, what is the point of my crossing the Indus? And after crossing — what then? Must I allow Harsha to capture me and have me hanged in Kanyakubja? I would rather die here with my people, die on Persian soil!”

The Grand Dastur pleaded insistently: “Your Majesty, your safety is bound up with the survival of our Persia!”

Yazdegerd III finally shed tears and said: “Four years ago I fled without a fight and abandoned the capital — it was this that brought about the fate of a ruined nation and destroyed people. From that day on, I resolved that wherever I went, I would stay with my people. I would not abandon a single one of them ever again.”

At this moment, the military commander Firuz, past fifty years of age, climbed to the mountaintop and bowed in salute before Yazdegerd III: “Your servant Firuz pays his respects to the King of Persia, the great King of Kings. I have good news to report to Your Majesty — the Arabs have withdrawn.”

Yazdegerd III was stunned: “Withdrawn? They had already surrounded me — why would they withdraw?”

General Firuz said: “At first I too did not understand, so I risked capturing an enemy soldier for interrogation. It turns out that the Arab Caliph had sent orders that we were only to be defeated and scattered, not annihilated — to be pressed hard and driven eastward.”

The Grand Dastur was astonished: “What do the Arabs mean by this?”

Yazdegerd III gave a bitter laugh: “Because the Arabs already know that I intend to break through the Indus River and take refuge in Tianzhu. They too wish to enter Tianzhu, but are hampered by the natural barrier of the Indus — and so they are using me to start a war with Harsha.” He then grew furious: “Have I really fallen into such contempt in the Arabs’ eyes? In their view, are the Persians nothing but a flock of sheep, to be herded about on the grasslands at their pleasure?”

The surrounding members of the royal family and the Dasturs all felt their spirits grow heavy. Even with the morning’s cold rain pouring over their heads, nothing could overcome the ice within their hearts. Yazdegerd III gazed eastward; beyond the rain-shrouded mountain ranges lay the land of Gandhara, and beyond Gandhara was the Indus River, formed from the confluence of five rivers — what the Tianzhu people called the Land of Five Rivers. The Land of Five Rivers was like Brahma’s great outstretched hand, guarding with its crisscrossing waterways, mysterious marshes, and rushing currents the vast, fertile, warm territory behind it — a land flowing everywhere with milk and honey. Yet even if he were to pierce through those rivers into Tianzhu over the bodies of hundreds of thousands of his people, it would in the end only be a gift for the Arabs. With Harsha ahead and the Arabs behind, the Sasanian Persian Empire’s only fate was to be slowly ground away by these two great rulers, bite by bite, and reduced to dust.

Yazdegerd III’s heart was bewildered. Where in the world can I possibly go?

General Firuz suggested: “Your Majesty, what of going north? If we could gain the acceptance of the kingdom of Tokharistan, we could advance by using the terrain to resist the Arabs, or retreat into the borders of the Great Tang and receive the protection of the Tang Empire. Three years ago you sent a letter of state to Emperor Li Shimin, imploring his assistance; he felt the distance was too great and did not send troops. If we draw closer…”

Yazdegerd III shook his head in sorrow: “Tokharistan is under the rule of the Western Turks, and you know the temperament of the Turks better than I do. Once our several hundred thousand people enter the steppe, we will be utterly swallowed by that wolf. I have already decided —”

Yazdegerd III savagely tore off his crown, letting his hair fall loose, and allowed the great rain to pour over his head. He raised his golden scepter and pointed east, bellowing with all his might: “I will lead you all to smash through the Indus River! I will seize a piece of land in Tianzhu and let the sacred fire of our Sasanian Persian Empire burn forever! I will wage war simultaneously against two great empires — if we cannot live, then we will die!”

The surrounding members of the royal family, the Dasturs, and the soldiers all cried out wildly together: “Live! Live! Live!”

Yazdegerd III roared: “Lift the sacred fires, follow in my footsteps — we cross the river!”

“Cross the river!”

“Cross the river!”

“Cross the river!”

The war cries rang out like thunder, shaking the mountains and the wilds. The Persians lashed great logs together around the sacred fire altars, and groups of a hundred men raised them onto their shoulders with a shout. Yazdegerd III walked at the very front, using the golden scepter to brace himself as he trekked through the mountain path against the wind and rain. More than five hundred men carrying the five great sacred fire altars followed in his wake; the sacred fires illuminated the easternmost border of the Sasanian Persian Empire, guiding the last of the Persians toward that land flowing with milk and honey.