This regime change in the Islamic world had very important consequences
for Byzantium. The dynamics of the relationship between the two central
governments changed, as the Abbasids initially sought to consolidate their
own leadership through championship of the jihad against Byzantium. Late
in the reign of their first caliph, al-Saffah (749–54), the large army that had
been mustered for use against Byzantium was diverted by its commander,
‘Abdallah bin ‘Ali, in an attempt to seize power for himself. His efforts
were thwarted,57 but this abortive coup d’´etat diverted Muslim resources at
a time when logistical considerations were making it increasingly difficult
for the Abbasids to wage war on Byzantium from their new capital under
construction at Baghdad. Under Caliph al-Mansur (754–75) the Byzantine
frontier was regarded as an area for Muslim settlement and fortification
rather than a theatre for major campaigning. Warfare became positional,
while the borders were now relatively static; some would argue that the
raiding became virtually ritualised.58
The Abbasid leaders had to reckon with possible Byzantine invasions,
and they also had to keep a close eye on the Muslim armies from northern
Mesopotamia, who still maintained their loyalties to the Marwanids. Various
border warlords also gave them cause for concern, particularly those
from the region of Samosata. To counter all these threats, al-Mansur tried
to coopt supporters of the last Umayyad caliph, Marwan II (744–50), and
he also imported troops from Khorasan. The result, however, was chaos and
anarchy on the borders. The caliph was forced to call on Abu Muslim –
who had led the Abbasids’ revolt against the Umayyads in 747, establishing
al-Mansur’s predecessor al-Saffah on the throne, and who was now governor
of Khorasan – for support to crush the rebellion of ‘Abdallah bin
‘Ali. Al-Mansur proceeded to develop his own network of border commanders,
of disparate origins, to serve as a counterbalance to the warlords.
No single Muslim commander was to lead an expedition against Byzantium
more than twice in succession. This rotation system was designed to
prevent any border commander from gaining control of really substantial
human and material resources. Yet it was also a precarious system, provoking
jealousy and competition among the local commanders and it did
not make for maximum military efficiency against the Byzantines. The
rotation system had been dropped by 769, towards the end of al-Mansur’s
caliphate, and thereafter al-Mansur sought to control the frontier regions
from a distance. Expeditions and leaders of expeditions had proliferated
because anyone with sufficient resources could try to mount an expedition
against Byzantium. The Abbasids now attempted to make permission from
the imam a necessary precondition for embarking on an expedition against
Byzantium.
During the caliphates of al-Mahdi (775–85), al-Hadi (785–86), and
Harun al-Rashid (786–809) warfare against the Byzantine empire became
a priority for the leadership. Al-Mahdi ordered the stationing of 2,000 new
troops at Mopsuestia, to be maintained by stipend, and his first campaign
against Byzantium was launched with aplomb in 776, with the caliph lending
his symbolic presence to the proceedings. In 778 the Byzantines, under
the Isaurian dynasty’s favoured commanderMichael Lachanodrakon, penetrated
the Hadath pass and attacked Germanikeia. Eventually the siege
was lifted (through the garrison commander’s bribery of Lachanodrakon,
according to Theophanes),59 but not before the Byzantines had deported
many Jacobite Christians to reside on the other side of the empire, in
Thrace. Emperor Leo IV (775–80) celebrated a triumph for his generals at
the palace of Sophianai on the Bosporus, distributing rewards. In the following
year, the Byzantines again penetrated to theHadath pass, provoking
a Muslim counter-expedition under Hasan bin Qahtaba, which reached –
but failed to capture – Dorylaion.
Henceforth Caliph al-Mahdi appointed frontier regional commanders
from his own household and family, aiming to raise them above the level
of the local border warlords. He accompanied an expedition as far as the
frontier region in 780 and from there he sent on his son, Harun al-Rashid,
who penetrated Byzantine territory and managed to besiege and capture
Semalous. In 781/2 al-Mahdi sent Harun to engage the Byzantine forces at
the head of a huge force, allegedly some 100,000 strong. After penetrating to
Chrysopolis, on the Asiatic side of the Bosporus opposite Constantinople,
and after seizing many captives, Harun imposed expensive and embarrassing
terms on Empress Irene in 782: the truce was to last for three years, and
involved an annual tribute payment by the Byzantines of 100,000 dinars; in
addition, Harun’s army kept its prisoners and considerable booty.60 Warfare
against the Byzantines now counted for more than it had done at any
time since the Umayyad caliphate of Hisham.
Harun al-Rashid resumed military operations in 785–6, in response to
an alleged violation of the truce in 785 and the Byzantines’ seizure and
destruction of the fortress of Hadath. From the Abbasids’ point of view,
the frontier system was not working very well and the Barmakid family
gained effective control of the caliphate’s north-west frontier provinces.
Nonetheless, Byzantium faced a formidable opponent when Harun al-
Rashid became caliph in 786; he had won great renown for his personal
participation in the jihad against Byzantium, and he had taken shrewd
advantage of Empress Irene’s weakness and her serious problems with her
military units (see above, p. 270). Around the time that Constantine VI
(780–97) was reigning in uneasy equilibrium with his mother,Harun chose
to make Raqqa his residence in order to control access to the frontier. In
797/8 Harun led the expedition that captured the Byzantine fortress at
Safsaf, not far from the Cilician Gates. The Muslims are even said to
have reached the Bosporus again, and Harun appointed commanders for
further raids. He agreed to negotiate with Byzantium only because of the
pressure he was coming under from the Khazars to his north. The caliph led
expeditions in person against Irene’s successorNikephoros I (802–11) in 803
and 806; during the latter expedition, Harun’s forces captured Heraclea-
Cybistra and Tyana, and the emperor was compelled to accept peace and
to pay a humiliating poll tax on himself and his son (see above, p. 256).
Harun took institutional measures to strengthen the caliphate’s position
against Byzantium in the long term. In the very first year of his caliphate,
he created a new frontier district called al-‘Awasim with Membij as its
centre. This marked the beginnings of a new system of frontier organisation.
Opposing the Byzantines along a straggling line from Tarsus northeastwards
as far as Theodosioupolis were the strongholds of the thughur,
subdivided into the thughurs of Syria and of the al-Jazira.61 These fortifications
ran through mountainous country from the Taurus in Cilicia towards
Germanikeia, and then on to Melitene. In 799 Harun built the town of
Haruniyya, named after himself, between Germanikeia and Anazarbos,
as part of his programme to organise and improve the defences of the
northern Syrian frontier. These strongholds on the front line were the culmination
of a long process that had already been underway before Harun’s
caliphate. But behind them Harun instituted the ‘awasim; these formed a
second, more compact buffer zone between northern Syria and the Cilician
thughur, extending from Antioch to Membij. Harun sought to break up
the conglomeration of north-west frontier provinces and to impose his own
personality directly on the frontier area and on the waging of jihad, thus
cutting down to size the figures of the local commanders and warlords.
The frontier became a centre of unprecedented attention in part because
of the accession to the throne of Nikephoros I in 802. Harun al-Rashid was
provoked by an insulting letter from Nikephoros, demanding the return
of the tribute that Irene had paid, but more important may have been
a Byzantine raid against Anazarbos and Kanisa al-Sawda. There was an
exchange of prisoners in 805 but, as mentioned above, in the following year
Harun imposed tribute of 30,000 dinars on Byzantium, in addition to the
poll tax that was payable by Nikephoros and his son. In 808 an exchange
of prisoners and a summer expedition into Byzantine territory took place,
but no further major Muslim expeditions into Byzantine territory would
occur until 830.
Harun’s commitment of so much energy and so many resources to his
wars against the Byzantines reflected his sense of duty, although some scholars
see his warfaring primarily as propaganda intended for internal consumption.
62 His wars brought few concrete territorial gains, but demonstrated
his personal involvement with the jihad.Harun may be characterised
as the first ghazi-caliph.63 For Hisham and theMarwanids, military service
had been a personal obligation, but Harun adopted the role of ghazi. He
owed his accession to the power base that he and his supporters controlled
in the north-western frontier regions, facing the Byzantines. He held himself
out as a ruler whose power was coterminous with Islam and also as an
imam-volunteer. Irene andNikephoros I could not match him as commanders
themselves and they lacked generals who were capable of resisting such
an effective leader.64 In this period some Muslim scholars and saints also
settled on the frontier, a trend that had not been typical of the Umayyad
era. Tarsus andMelitene emerged as the principal centres of the thughur by
the mid-ninth century, and part of their population was made up of ghazivolunteers.
Some commercial goods passed through these strongholds to
and from Byzantine territory, and professional military men tried to wield
power there.
World History
