Halabiye (Hammat al-Shamiyah) patrolled the shores of the only "stranglehold", or gorge, on the great blue-green Euphrates, along the fiercely guarded eastern frontier of the Roman Empire, 58 kilometers north of present-day Deir Ezzor within the precinct of al-Tibni, and 165 kilometers northeast of Palmyra whose trade it long administered.

A Palmyrene commercial and military outpost of great importance during the third century A.D., divided by the river and by strategic convenience in two parts, the mighty fortress walls and their parent citadel, on a steep conical hill lifting one hundred meters off the valley floor, were confected of local hammat or lava, combined with the glittering native gypsum. The result was a stronghold that shimmered from a distance but at close range was ominous, conceived and constructed specifically for the defense of the cliffs that formed the narrow pass known as the al-Khanuqa, "The Strangler" or "The Suffocator", part of an extension of the al-Bishri range that interrupted the otherwise unbroken terraces and plains on both sides of the river.

The spectacular remains still visible in Halabiye largely correspond to the Byzantine era. They were judiciously erected during Justinian's far-reaching policy of securing the Euphrates against the Persians, but the site, known to the Assyrians as Ninqoshaborat, and having been razed during the Aramean period, was recreated during its Palmyrene days. It was, in fact, rebaptized in honor of the enterprising and rebellious Queen Zenobia (al-Zabba'a), before again being destroyed by the Romans.

Before its plush days on the Palmyrene trade routes, or its brush with either Imperial Rome or the Byzantines, Halabiye had a long history. References to the site appear in the lists of the Assyrian king Ashurnasirpal I ("Ashur Guards the Heir", c. 1050-1031 B.C.), son of Shamshi-Adad IV and grandson of the great Tiglath-Pileser I.

Later construction probably corresponded to the venerable fortress city-state of Dur Karbani, c. 877 B.C., built at the order of Ashurnasirpal's namesake, Ashurnasirpal II, son of Tukulti-Ninurta II. Dur Karbani was reputed at one point to have been the seat of the god Assur, and as such, a burial site for Assyrian monarchs. Certainly tombs, from the Assyrian period as well as the Palmyrene, were conspicuous in the cliff walls facing the river.

The construction of public works, such as canals, dykes, city walls and quays, as well as the design and confection of palaces, tombs and temples, was the domain of kings, delegated in turn to the provincial governors. Third millennium Mesopotamian tablets listed the name of the person responsible for the erecting or restoring of any building project, described its purpose, and usually included a date; the information was then deposited inside the finished construction. Building inscriptions were often the only evidence of the existence of a public official. The custom, embraced by the Assyrians, was so effective it was willingly adopted by other cultures of the ancient Near East.

Building inscriptions from the first millennium, especially from the neo-Babylonian (Chaldean) and neo-Assyrian periods, were sometimes several hundreds of lines long, and gave lengthy burocratic accounts of the large-scale public works projects of the times. Such was the case with the inscriptions ordered by Ashurnasirpal II, installed in Nineveh, Ashur, Balawat and Apqu (Tell Abu Marya), which not only documented construction projects but, in addition, reported the details of fourteen major military campaigns undertaken before 866 B.C., when the records end.

Ashurnasirpal II extended Assyrian power farther than his father ever had. He crossed the Euphrates, reached the Mediterranean and received tribute from states as far south as Tyre. The Ashurnasirpal journals report little opposition in the Levant, but in eastern Syria, presumably in Halabiye among other prosperous city-states -- rich in silver, gold, copper, precious stones, dyes and pigments, and camels, and administered by provincial governors or vassal princes who had submitted to Ashurnasirpal's father -- revolt had been encouraged by the kingdom of Bit-Adini, whose population was apparently resolved to suspend all tribute to the Assyrians. The king was merciless in his repression of the rebels, and furthermore, plundered the towns and erected inscribed stelae to commemorate each victory.

Assyrian presence was further documented in bas-reliefs, whose aesthetic richness, innovation and dexterity have dazzled spectators in all the world's greatest museums of art or archaeology. One mural panel, for example, portrays Ashurnasirpal's journey through the staggered layers of cliffs and pinnacles of a stylized mountainous landscape bordering a river, in turn illustrated by means of wavy lines and spirals. The king's carriage, the three matched steeds pulling it, the servants carrying a parasol against the rays of the sun or the arrows prepared in case of attack, the quivers and lances, pull up at a fortress. Another mural panel shows them mounting a siege against the resident population, and portrays the architecture of the citadel and defensive strategies in vogue at the time, as well as the drawing of water from the river.

One particular incident in Ashurnasirpal's annals, c. 878 B.C., describes the revolt of the Zuhi, an Aramean vassal state occupying the Halabiye region, and serves as the subject of one of the most noteworthy and memorable of all the murals, a masterpiece of its kind, in which the king, on campaign along the Euphrates, finds that "Here, confronted by my insurmountable weaponry, Kudurru and seventy of his soldiers have flung themselves into the waters of the great river. They are held afloat by goatskins and they are swimming for their lives." Archers aim at them from the bastions along the fortress walls. Date palms loom in the distance.

The site, strategic and easily protected, though originally, according to texts of the time, a Babylonian hegemony that later corresponded to Assyrian dominion, was especially prized by Arameans, whose principalities, or fiefdoms, came to dot the cliffs and shores along "The Strangler". The Zuhi Princedom confined itself principally to the headlands of Zalabiye (Hammat al-Zalobia), Halabiye's sister city, just three kilometers south of the main fortress, across the river on the eastern bank. The Laqi Princedom dominated the Halabiye region between the Khabur and the Bleikh. Between them they managed to patrol traffic along the river, keeping contraband and illegal immigration to a minimum. To this day the locals refer to Halabiye as Lyja, implying the ancient Laqi, despite the fact that a vengeful Ashurnasirpal, who used the site as an example before the neighboring clans, decimated its population. He also razed Halabiye, then ordered new fortresses built, one on the western bank which he called Nibart Ashur, and the other on the eastern bank, called, until the fall of the Ashur Dynasty in 668 B.C., Karkh Ashurnasirpal.

So thorough were the superimpositions of people over places that the succession of habitation was lost. When Alexander arrived there were remains of several construction phases in the Halabiye pass, all demolished. Only the memory of their names remained: Telda (probably Zalabiye), Massilia just to the north of Zalabiye, and Anukas wedged into the narrow waterway. In addition to its strategic potential the fertility of the area was legendary, and so it was documented by Roman geographer-historian Strabo. "The land produces barley in quantities that no other land does, even, they say, three hundredfold. Its other requirements are provided by the palm-tree, namely bread, wine, vinegar, honey and grain-meal; and all other kinds of textiles come from it; and the bronzesmiths use the kernels in place of charcoal, and these when soaked are fodder for the oxen and sheep which are being fattened."

Alexander entertained the idea of renovating a canal in this region, so that in the dry season it could be more easily dammed and the Euphrates remain full. According to historian Arrian, "There he founded a city and walled it, and in it he settled certain Greek mercenaries, some of whom volunteered while others were unfit for war through age or wounds."

The Middle Euphrates valley, throughout the Seleucid period, had been dominated by the influence of the Parthians. The trading posts they had established in Halabiye, and downriver in Doura Europos, were ultimately, however, consigned to Palmyrene management for the transshipment of the goods that traveled between the markets of Iraq and Central Asia on the one hand, and Damascus and the Mediterranean on the other. The Palmyrenes, consummate merchants, and with Parthian collaboration, carefully fortified their defenses of the straits, built river wharfs and warehouses for their merchandise and, as Alexander had intended, dams to control the river's level.

Tempted by the wealth and arrogance of Palmyra, that were by now celebrated by both scribes and troubadours, in epic and in legend, Mark Anthony, following his skirmishes against the Parthians in Damascus in 36 B.C., marched out to plunder the desert emporium, but the resourceful Palmyrenes gathered their goods and their families and moved out to Halabiye. The Roman general followed them. The Palmyrenes defended their fortress city on the Euphrates, and defeated Mark Anthony, only to be raided again by Anthony's Roman troops, in 41 B.C. Both Halabiye and Zalabiye were ravaged and razed to the ground.

Disciplined, tenacious, cultivated and courageous, though also dangerously ambitious, the legendary warrior queen, known by the Greek name of Zenobia, rose to power well after the zenith of Roman domination on the eastern front. Following the murder of her husband Odenathus II- an assassination whose perpetrators were never clearly identified-and acting as regent for her young son, Wahab al-Lat, she was able to consolidate the power of the wealthy and influential Palmyrene state in her own hands while she capitalized shrewdly on the weakness she felt at the heart of Rome. She visualized, say her admirers, a new dynasty, with herself at the helm, a strictly Palmyrene realm; and managed to bring Cappadocia, Galatia and most of Bithynia under her control. She then fitted out a great army and fleet, conquered Egypt, and took Alexandria after a siege that destroyed half the population, leaving her son in charge of the province. And so the "Queen of the East", in the guise of an "agent of Roman authority", actually played a key role, say her detractors, in the exquisitely multifaceted drama of Rome's slow-motion collapse.

Aurelian, however, Rome's implacable "Hand on Sword", responded to Zenobia's rebellion by quickly recovering Egypt, and by occupying Palmyra in 272 A.D. When the Queen tried to escape to her eastern fortress in Halabiye, in the hopes of enlisting Persian aid to her cause, she was captured and taken in chains to Rome. Palmyra was devastated and Halabiye was razed.

A desperate Diocletian, eager to revitalize the waning power of Pax Romana, may have rebuilt the Halabiye fortifications as part of the defenses of the Syrian limes or boundaries, and further repair under Anastasias (491-518) is more than likely.

It was nonetheless the obsessive Justinian, who reigned from 527 until 565, in his relentless counterpoint to the Sassanian Persians, who instrumented Halabiye's most effective construction phase, and the mythic magnificence of the massive square bastions, this time intended as a significant pawn in a Christian kingdom, and reinforcement for the fortress-city and pilgrimage site at Resafa. His general Belisarius, to this effect, carried out several important campaigns, while an architectural team was directed by the nephew of Isidorus of Miletus, and masons included Maltese Knights of St. John.

The bold project was all carefully described by the prolific Procopius, chronicler and legal consultant to Belisarius, and Justinian's historian and enemy. The scribe viewed Justinian as "insincere, crafty, hypocritical, dissembling his anger, double dealing, clever, a perfect artist in acting out an opinion which he pretended to hold, and even able to produce tears to the need of the moment."

At the same time, said Procopius, the emperor subscribed to pomp and ceremony at his court, beyond even the precedents of Diocletian or Constantine. "Like Napoleon," says the modern historian Will Durant, "he keenly missed the support of legitimacy", having succeeded to a usurper. "He had no prestige of presence or origin." So he encouraged, decried Procopius, the Oriental notion of royalty as divine.

Justinian's great works on the eastern frontier, it was said, were only made possible because of the treaties he signed, and often betrayed, and the respite they provided, with his most insidious rival. Khosru I, ("Fair Glory", 531-579 A.D.), the greatest of Sassanian kings, was called Chosroes by the Greeks, Kisra by the Arabs. The Persians added Anushirvan ("Immortal Soul"). The venomous Procopius described him as "a past master at feigning piety". The Persian historian al-Tabari, on the other hand, with infinite magnanimity, praised Khosru's "penetration, knowledge, intelligence, courage, and prudence". He surrounded himself, said his chronicler, with philosophers, physicians and scholars from India and Greece.

Khosru I completely reorganized the government, chose his aides for their ability regardless of rank, and replaced untrained feudal conscripts with a standing army both disciplined and competent. He established a more equitable system of taxation, built dams and canals, added drainage to the cities and irrigation to the farmland, and reclaimed waste lands by offering concessions on cattle, farm implements and seed. He fostered commerce by the construction, repair and protection of bridges and roads. He persuaded bachelors to marry, and educated their children with state funds. Against such visionary measures Justinian's grand scheme was doomed to failure, and history deemed Khosru I the greater king. Justinian's fixed defenses at Halabiye, undermanned, could do little but contemplate the contraband Persian traffic, defended by agile and well motivated Sassanian troops.

Persian supremacy was prolonged during the subsequent reign of the Greek emperor Maurice, when a new Sassanian king, Khosru II Parvez ("Victorious"), rose to greater heights than any Persian monarch since Xerxes, yet set the stage for his empire's complete destruction. And while he had agreed to withdraw from Armenia, and Ctesiphon had the rare experience, in 596, of seeing Maurice's Roman army install a Persian king, Caesar Phocas murdered and replaced Maurice. Parvez declared war on the usurper, and to avenge his friend, a holy war against the Christians. The Holy Sepulchre was burned to the ground and the True Cross was carried off to Persia. "Alexander has at last been answered." The battle between Persia and the Byzantines ebbed and flowed until Heraclius, in response to the desecration of Jerusalem, sacked Clorumia, birthplace of Zoroaster, and was finally instrumental in Khosru's being put to death in 628. By then, terror and devastation had finished Halabiye, and set the stage for the Arab advance.

The sealing of the Euphrates frontier was never an issue with the Arabs. On the contrary, the Umayyads hoped to breach the barriers between Syria and Mesopotamia, and the Abbassids in fact opened the region to trade and migration across Iran and beyond the Caspian. The great Halabiye fortress, meanwhile, was simply left to decay. The scant population remaining in the region had no need for the stones. The only deterioration was caused by earthquake, or by the river's flooding along the 385 meters of the embankment walls.

The golden gypsum walls, turned russet and pink by the late afternoon sun, contained a small garrison city within a twelve-hectare precinct. The 550 meter-long south wall and the 350-meter long north wall inch bravely up the steep, rocky slopes until they converge on the ruins of the citadel, thus forming an irregular triangle that has survived, in part because of the careful Byzantine construction superimposed on a typically stolid Euphrates style, but mostly because of the gigantic size of the stones. There is a monumental gateway in each of these walls. The three grand gateways in the embankment walls, which led to the wharves, have long since collapsed or been swept away by the great river.

The colossal lateral walls are protected from outside the city by wadis, that were controlled by dams, still in evidence, and which shielded the tower tombs or the rock-cut tombs in the cliff face. From the inside the walls are governed by square towers connected, a strategy dear to Justinian, by a series of inner corridors. Each tower is equipped with a massive portal, and elaborate interior stairways, which offer access to the crenellated ramparts. When I tried to climb one of these a snake blocked my way. We stared at each other until it finally slithered into the cracks between the huge blocks of stone.

The forward face of the triangle, parallel to the river, was skirted by an east-west colonnaded Cardo Maximus, intersected by a north-south artery. Marble columns and their Corinthian capitals are scattered at random. At the junction of the two avenues were the baths, the forum, and two churches. The smaller church, perhaps once a temple, was the earlier, while the larger would appear to date from the Justinian era.

In the northern wall are lodged the remains of a Praetorian gatehouse, inside one of the square towers. Farther up the excruciatingly steep hill are the precarious ruins of a three-storied palace, badly damaged by earthquake, its brick-vaulted ceilings and soaring stone arches held aloft on prayer alone. Access to the interior is blocked and exploration is risky, but irresistible. The palace may have been used well into the Islamic period.

A legend claimed that Queen Zenobia had a sister, for whom she built a palace, connected to her own by a tunnel, which additionally served as a refuge from would-be invaders. No traces of a tunnel were ever found, and in all likelihood, there never was a sister, either. The tunnel, if it ever existed, was probably an escape route, or the legend of one, that extended, the story goes, from under Zenobia's bed to under her sister's. The tale is nevertheless presumed to be related somehow to the two-story bridge that connected the twin fortress cities. The ruins of the piers of the bridge are still visible in September, when the level of the water is at its lowest.

Today a pontoon bridge with a washboard floor connects the two sides of the river, so a car bounces breathily along, seemingly at the very surface of the agate-colored water. A lone donkey crosses the railroad tracks on the other side. The narrow-gauge line services a gravel plant that lies just under the hill, now windblown and largely vacant, where Zalabiye once stood. There is little in the way of ruins but the view from the headlands up and down the blithe river, so insolent, so omnipotent, makes the windy walk well worthwhile.

Excavations and mapping of Halabiye and Zalabiye began in 1936 when the Yale University team, working in Doura Europos, intervened in the site. French archaeologist Georges Louvret led additional excavations in 1945. The porcelain vases, inscriptions and fragments of textiles he unearthed, mostly from the palace and Praetorian guardhouse, are displayed in the National Museum in Damascus.

Carol Miller is a sculptress and writer, devoted to her avid research of ancient cultures, from Mexico where she lives, or along her travels throughout the world. "Mari" is a chapter from a forthcoming book, soon to be available at Amazon.com or BarnesandNoble.com. Among her titles are "The Winged Prophet, from Hermes to Quetzalcoatl", with Guadalupe Rivera Marin, a study in comparative mythology; and "Travels in the Maya World", "The Other Side of Yesterday, the China-Maya Connection" and "Training Juan Domingo: Mexico and Me", exerpts of which can be viewed at http://www.xlibris.com/CarolMiller.html