Under Maurice Priscus first appears in the historical sources when he was appointed, in late 587 or early 588, to command in the East
against the Persians as
magister militum per Orientem, replacing
Philippicus. He only reached the East in spring, and assumed his new command at Monocarton in April. Priscus immediately ran into trouble with the soldiers: his haughty manner in refusing to mingle with them made him unpopular, and when a decree by Emperor Maurice which reduced army pay by a quarter was announced, the soldiers mutinied on
Easter day, 18 April 588. Priscus not only failed to restore order, but was himself attacked and forced to flee to
Constantina, while the soldiers elected the
dux of
Phoenice,
Germanus, as their leader. Priscus's attempts from Constantina to calm the soldiers by employing the local bishops as mediators and rescinding the decree also failed. Philippicus was restored to command by Maurice, while Priscus returned to
Constantinople. Despite this debacle, in the same summer he was entrusted with the post of
magister militum for
Thrace, and tasked with campaigning against the
Avars at the head of an improvised force. His deputy (
hypostrategos) Salvianus with 1,000 cavalry was sent to hold the passes of the
Haemus Mountains, but after two days was forced by the Avars' numerical superiority to withdraw. The Avars sacked the city of
Anchialos, but an attempted siege of
Drizipera was broken off and the Avars marched south, reaching
Heraclea Perinthus and cutting Priscus's forces off from Constantinople. Outflanked, Priscus retreated to
Tzurullum, where he was besieged by the Avars. The 7th-century historian
Theophylact Simocatta reports that after a few days, Priscus devised a stratagem to force the Avars to withdraw: he allowed one of his guards to be captured, bearing a fake letter purportedly coming from Maurice that informed Priscus of a seaborne attack against the Avars' homeland. The Avar
khagan was persuaded that the letter was true and prepared to return home in haste; he arranged for a truce in exchange for the renewed payment of an annual tribute. The 12th-century history of
Michael the Syrian gives this as 800 pounds of gold (some 60,000
solidi), a considerably reduced sum compared to the 100,000
solidi agreed in 584. The Avars departed for their country, while Priscus disbanded his army and returned to Constantinople. Priscus disappears for the next few years, as he fell into disfavour with Maurice. By 593, he had recovered his position, as a letter by Pope
Gregory the Great which congratulates him on returning to the emperor's favour testifies. The Pope's letter also testifies that by this time, Priscus had been given the Empire's supreme honorary rank, that of
patrikios. In spring 593, Priscus was re-appointed in command as commander of the cavalry in Thrace, with
Gentzon leading the infantry. Priscus, as the more senior of the two, also held overall command. Both generals marched to
Dorostolon on the
Danube, and campaigned with success against the Slavic tribes preparing to cross the river under their leaders
Ardagastus and
Musocius. Crossing the river, both Slavic hosts were annihilated in surprise night attacks. At the same time, however, Priscus reportedly quarrelled with his men over the distribution of the booty captured, and especially the considerable portion Priscus allocated to the imperial family. The soldiers were eventually placated, and the booty sent back to the capital with an escort. Maurice also sent orders for the army to winter north of the river, but this caused great resentment and unrest amongst the soldiers. Priscus chose to disobey the emperor's order and crossed again with his army to winter in the southern bank. In the autumn of 593, he was replaced by Maurice with his own brother
Peter. Before the latter could assume command, however, Priscus arranged for a truce with the
khagan, to whom he returned all Avar captives, some 5,000 in number, a fact for which he was criticized by Maurice. In late 594, however, after Peter was heavily defeated by the Slavs, Priscus was again appointed to command as
magister militum of Thrace, a post he proceeded to hold continuously for several years. In 595, he marched up the Danube, crossing the river and marching along its northern bank to
Novae, despite the
khagan's protests. There, he learned that
Singidunum had been captured by the Avars. He sailed his army to the city and, after failed face-to-face negotiations with the
khagan, sent the
taxiarches Guduin to recapture it. The Avars, having razed the city's walls, abandoned it at the approach of the Byzantine force. Next the Avars launched a raid against
Dalmatia. Guduin was dispatched with 2,000 men to shadow them. He managed to ambush the Avar detachment carrying their booty, recovered it and sent it to Priscus. After these events, the
khagan turned west to campaign against the
Bavarians and the
Franks, leaving the Byzantine territories quiet for a period of a year and a half, until the summer of 597. Nevertheless, Priscus and his army remained on watch along the Danube border. '' of Emperor
Maurice (r. 582–602). When the Avars resumed their operations with a large invasion in autumn 597, they appear to have caught Priscus, who was probably operating with his army at the eastern
Stara Planina, off guard. They advanced quickly, and even managed to bottle up and besiege Priscus and his men at the port of
Tomi, until the approach of a freshly raised army under
Comentiolus forced them to abandon the siege on Easter day, 30 March 598. Priscus, however, remained strangely inactive, and Comentiolus's inexperienced army was routed in battle. The Avars then advanced south into Thrace, forcing Maurice to garrison the
Anastasian Wall to prevent an attack on Constantinople. The Avar army, however, was decimated by a
plague, and a treaty was quickly concluded, whereby the Avars retreated beyond the Danube in exchange for an increased annual tribute of 120,000
solidi. The Byzantines used the time to regroup their forces, and in the summer of 599, two armies under Priscus and Comentiolus headed west along the Danube. At
Viminacium, Comentiolus fell ill and Priscus assumed sole command of the campaign. His army crossed the river, and fought
three successive battles over ten days. These battles were won by the Byzantines, who, according to the account of Theophylact Simocatta, killed 28,000 barbarians in total, including some of the sons of the
khagan. Priscus pursued the fleeing
khagan and invaded the Avar homeland in
Pannonia. There, a fourth battle was fought near the river
Tisa, which was also won by the Byzantines. On the very next day, Priscus dispatched a reconnaissance force across the river, which attacked three
Gepid settlements by surprise. According to Simocatta, 30,000 were killed and many were taken captive. Nineteen days later, another great battle was fought by the Tisza, which ended in a decisive Byzantine victory: the Avars and especially their Slavic allies suffered greatly, and Priscus took 3,000 Avars, 8,000 Slavs, and 6,200 other barbarians captive, who were sent south as slaves. Maurice, who had not yet realized the extent of his army's victory, ordered their release as a gesture of goodwill to the
khagan. Nevertheless, Priscus's campaign was a remarkable act of aggressive defence. In the words of Michael Whitby, the main modern expert on Maurice's reign, it was "without parallel in the sixth century" for the Danube frontier, and which essentially decided the war for Byzantium. After this success, which secured the Balkans, Maurice intended to consolidate Roman control by bringing in
Armenian settlers who would be given land in exchange for military service. To this end, Priscus was sent to
Armenia to recruit men and their families. His mission there, however, was interrupted by a large-scale military revolt that brought about the downfall of Maurice. In 602, Maurice again ordered his troops on the Danube frontier to winter north of the river. Again, this provoked widespread discontent, and when Peter, who had replaced Priscus, refused to bow down and rescind the order, an outright mutiny broke out. The army chose the officer
Phocas as its new leader and marched down to Constantinople. Without any credible military forces of his own, Maurice had to flee, but was captured with his family and executed by Phocas, who now became emperor.
Under Phocas (r. 602–610). Due to his absence from Constantinople at the time of Phocas's takeover, and because he retained a large measure of support within the soldiery, Priscus was the only one of Maurice's senior generals who was retained by the new regime, whereas Comentiolus and Peter were executed and Philippicus was banished to a
monastery. A possible explanation for this comes from the later historian
Paul the Deacon, who records, possibly based on early 7th-century sources, that Phocas had once served as an
equerry under Priscus. At any rate, Priscus was soon counted among the main supporters of the new regime. Phocas's rule lacked legitimacy and quickly came to be resented by the populace and the elites of the Byzantine Empire. What prestige he had further eroded when the Persian shah
Khosrau II (r. 590–628) declared
war, and when the Byzantine forces began to suffer their first defeats. According to a later tradition, Priscus sent a letter to the
Exarch of Africa,
Heraclius the Elder, urging him to revolt. This is probably a later invention, but if true, it would indicate the level of dissent even within Constantinople. Whatever the truth of the matter, in 608 Africa
rose in revolt, and the Exarch's son,
Heraclius the Younger, was dispatched against Constantinople at the head of a fleet. Unopposed by Phocas's forces, he landed at the suburb of
Hebdomon on October 3 and marched to the capital, where pro-Heraclian riots had broken out. At this juncture, Priscus pretended to be ill, and withdrew to his mansion at the
Boraïdou quarter, where he assembled the
excubitores and his own retainers (
bucellarii), thus depriving Phocas of his main source of armed support. He is also recorded by
John of Nikiu to have safeguarded the women of Heraclius's family from retribution by Phocas.
Under Heraclius (r. 610–641). After Phocas's fall, Heraclius became emperor of Byzantium. The
Patriarch Nikephoros claims in his
Short History that the crown was first offered to Priscus, who refused it. As commander of the
excubitores, a
protopatrikios (first among the patrician order) and one of the few senior and influential officials with ties to past regimes, Priscus represented a potential threat to Heraclius. Nevertheless, facing a critical situation in the East, where the Persians had overrun much territory and were raiding
Anatolia, Heraclius appointed Priscus in command of the Anatolian army in the autumn of 611. The Persian general
Shahin captured
Caesarea in
Cappadocia, only to be
blockaded and besieged there by Priscus. Heraclius himself decided to visit the army camp at Caesarea during winter, but Priscus refused to meet him, on the pretext of an illness. This snub alienated Heraclius from his general, and when Shahin and his army managed to break out and escape in summer, Priscus was recalled to Constantinople, ostensibly to become godfather to the Byzantine emperor's son,
Heraclius Constantine. At the capital, he was removed from his post as
comes excubitorum, which went to Heraclius's cousin
Nicetas, while command in Anatolia went to the other surviving general of Maurice, Philippicus, brought out of retirement. Priscus was brought before the
Byzantine Senate and accused by Heraclius of treason. In the end, he was
tonsured as a
monk on 5 December 612 and confined in the
Monastery of the Chora, where he died in 613. ==Assessment==