The low state of medieval maritime technology ensured that
battle tactics were just as basic. They had hardly progressed since Roman
times. Confrontations at sea remained messy affairs that almost invariably
devolved into unpredictable ship-against-ship mêlées. This helps explain why
large-scale naval engagements were rare during the Middle Ages. Few naval
commanders were willing to risk all in a single battle subject to so many
uncontrollable variables. As on land, clashes at sea normally occurred only when
one side or both could not avoid it.
The fact that there was no reliable ship-killing weapon
compounded the uncertainty surrounding the outcome. The waterline ram or
rostrum of the classical era was ineffective against the sturdier, frame-first
hull construction which began to develop in the Mediterranean as early as the
seventh century and found full implementation by the eleventh century. It
proved utterly futile against the more robust ship architecture of the northern
seas, even in Roman times. In his Commentarii de Bello Gallico (‘Commentaries
on the Gallic War’), Julius Caesar said of the dense oak vessels of the Gauls,
‘Our ships could not damage them with the ram (they were so stoutly built).’ As
a result, no warship in either the north or the south was known to have sported
a ram by the seventh century. It was replaced on the Byzantine dromōn by a
spur, a sort of reinforced bowsprit used to assist in seizing and boarding an
enemy ship. The only weapon developed in the medieval period capable of
destroying an entire vessel was ‘Greek fire’, a secret petroleum-based
incendiary invented by a Syrian artificer named Kallinikos in the seventh
century. Documentary and graphic sources indicate that it was spewed from
specially constructed siphon tubes mounted on the bows of dromōns. Unfortunately
its utility was extremely restricted. It had limited range and could only be
deployed in calm or following winds.
Siphons for spewing ‘Greek fire’ were eventually mounted on
protected platforms at the bow and possibly amidships. The parapeted forecastle
(xylokastron) housed the main siphon, called the ‘raven’ (katakorax), while the
castle amidships was the kastelloma. The aftercastle contained the kravatos, a
structure to shield the kentarchos or captain.
The First Siege of Constantinople and the Advent of
‘Greek Fire’ (672–7)
Once Muawiyah had moved his capital to Damascus and
consolidated his grip on power, he began preparations for an enormous
expedition against Constantinople itself. In 672 he was ready. The caliph
unleashed at least two separate fleets on the south coast of Asia Minor. Their
activities must have kept the Karabisian fleet fully occupied. Both Crete and
Rhodes were raided. One Arab fleet wintered in Cilicia (the southeastern coast
of Anatolia) and the other in Lycia (on the south-central coast). Word of these
incursions galvanized Constans’ son and successor, Constantine IV, into action.
According to Theophanes, the emperor ‘built large biremes bearing cauldrons of
fire and dromones equipped with siphons and ordered them to be stationed at the
Proclianesian harbour of Caesarius [Constantinople’s Theodosian harbour]’. In
673 Muawiyah’s fleets surged into the Sea of Marmara and ravaged the Hebdomon
district just southwest of Constantinople, then captured Kyzikos on the south
shore of the sea. Here they established a base camp for incessant attacks on
the city.
Constantinople would endure this maritime assault for the
next several years, but the emperor was in possession of a terrible new weapon
which would finally – and precipitously – end it. Residing in the city at that
time was a Christian refugee from Heliopolis in Syria (modern Baalbek in Lebanon)
named Kallinikos. Theophanes described him as an ‘architect’ or ‘artificer’ who
had ‘manufactured a naval fire [or sea fire]’ which floated on the surface of
the sea and could not be extinguished by water. Its precise ingredients were
kept a closely guarded state secret and remain a mystery to this day. This has
led to endless speculation through the ages and repeated attempts at
replication. A similar Muslim concoction of the twelfth century was said to
have included ‘dolphin’s fat’ and ‘grease of goat kidneys’. Early scholarly
conjecture centred on saltpetre as the main component (as in gunpowder) or some
form of quicklime, but recent empirical investigations, particularly by
renowned Byzantinist John Haldon, have revealed that its primary ingredient was
probably petroleum-based – most likely naphtha or light crude oil. The
Byzantines had access to the oil fields of the Caucasus region northeast of the
Black Sea where crude seeped to the surface. The theory is that Kallinikos may
have distilled this into a paraffin or kerosene, then added wood resins as a
thickening agent. The mixture was then heated in an air-tight bronze tank over
a brazier and pressured by use of a force pump. The final step was the release
of the flammable fluid through a valve for its discharge from a metal-sheathed
nozzle, affixed with a flame ignition source. In a 2002 clinical test of this
theory, Haldon and his colleagues, Colin Hewes and Andrew Lacey, were able to
produce a fire stream in the neighbourhood of 1,000 degrees Celsius that
extended at least 15m (49ft).
It was very probably a compound similar to this that
Constantine caused to be loaded onto his dromōns in the autumn of 677. The
fearsome new weapon was unleashed from swivel-mounted siphons in the
forecastles with horrific results. Theophanes testified almost matter-of-factly
that it ‘kindled the ships of the Arabs and burnt them and their crews’. To the
Arab victims of his frightful invention, it must have seemed like some early
version of ‘shock and awe’. The fact that they would have had no idea of how to
combat the weapon must have compounded their panic. Water would have been
ineffective. At that point they could not have known that the only way to
extinguish the ‘liquid fire’ was with sand, vinegar or urine. The siege soon
collapsed. What was left of the Arab armada withdrew, only to be severely
mauled by a violent winter storm while passing abeam Syllaem in Pamphylia (on
the south coast of Asia Minor between Lycia and Cilicia). Theophanes said, ‘It
was dashed to pieces and perished entirely.’
The Second Siege of Constantinople and the Fall of the
Umayyad Dynasty (717–50)
The continuing turmoil in Constantinople could not have gone
unnoticed in Damascus. Earlier that same year Sulayman ibn Abd al-Malik assumed
the caliphate and inaugurated his rule by propelling his brother, Maslamah ibn
Abd al-Malik, into Asia Minor at the head of 80,000 troops, while a huge armada
of reportedly 1,800 vessels made its way around the south coast. Constantinople
was about to experience its most dire confrontation with Islam until its final
fall over seven centuries later.
The details of the ensuing epic engagement are discussed in
a separate section at the end of the chapter as an example of sea combat in the
period, but it suffices to say here that it unfolded in a manner similar to the
siege of 672–8, with much the same result. As the Arab forces approached
Constantinople in the spring of 717, Leo the Isaurian, the strategos of the
Anatolikon Theme, engineered a coup to replace the ill-suited Theodosios III on
the throne. Under his inspired leadership as Leo III, the Byzantines then used
dromōns spewing ‘Greek fire’ to break up an Umayyad attempt to blockade the
Bosporus. The besieging Arab army fared even worse. A particularly harsh winter
ravaged it with deprivation and disease. And the following spring offered
little relief. Nearly 800 supply ships arrived from Egypt and Ifriqiyah, but
their Coptic Christian crews switched sides en masse. Without the precious
provisions which these ships carried, Maslama’s troops fell easy prey to the
Bulgars of Khan Tervel, with whom Leo had formed a propitious alliance. The
Bulgars butchered some 22,000 of the Arabs. Umar ibn Abd al-Aziz, the new
caliph, had little choice but to recall his forces. It was a battered Umayyad
army that retreated across Asia Minor in the autumn of 718 and only five
vessels of the once massive Muslim armada managed to run the gauntlet of autumn
storms in the Hellespont and Aegean to reach their home port.
It was a disastrous Muslim defeat, which should have put
Islam on the defensive for decades to come, but inexplicably Leo chose this
time to delve into the religious controversy that was to be the bane of
Byzantium. In 726 he inaugurated Iconoclasm (literally, ‘the smashing of
icons’) by ordering the removal of the icon of Christ over the Chalke entrance
to the imperial palace in Constantinople. In 730 he followed up this action
with an imperial decree against all icons. This polemical policy was to rend the
fabric of the empire for the next fifty-seven years. It proved particularly
unpopular in Italy and the Aegean areas. In early 727 the fleets of the Hellas
and Karabisian Themes revolted and proclaimed a certain Kosmas as emperor. Leo
managed to devastate and disperse these fleets with his own, again using ‘Greek
fire’, the secret of which was apparently restricted to Constantinople at the
time.
The episode, nonetheless, prompted the emperor to dissolve
the troublesome Karabisian Theme and restructure the provincial fleets in order
to dilute their threat to the throne. Leo placed the south coast of Asia Minor,
formerly a responsibility of the disbanded Karabisian Theme, under the
authority of the more tractable droungarios of the Kibyrrhaeot fleet, whose headquarters
was transferred to Attaleia (present-day Antalya). Land-based themes, like the
Hellas and Peloponnesos, were also allowed to maintain fleets of their own.
These modifications to fleet organization were probably intended to help defuse
naval power and make it more subservient to the emperor.
Despite their humiliating failure before the walls of Constantinople, the Umayyads took advantage of continued Byzantine upheaval both in the palace and in the Church to nibble away at the edges of the empire. A long period of raid and counter-raid ensued between Damascus and Constantinople, mostly involving either Egypt or Cyprus. But ultimately the Byzantines’ advantage in naval organization, possession of ‘Greek fire’ and virtual monopoly of such critical shipbuilding materials as wood and iron ensured they would prevail, at least in the eastern Mediterranean. The climax of the contest came in 747, when the Kibyrrhaeot fleet surprised an enormous armada from Alexandria in a harbour on Cyprus called Keramaia (exact location unknown). ‘Out of 1,000 dromōns it is said only three escaped,’ professed Theophanes. This was undoubtedly a chauvinistic exaggeration, but Umayyad naval power was evidently broken by the outcome of the battle and never again posed a serious threat to the Byzantine Empire. The Umayyad Dynasty came to an end just three years later when the Abbasids led by Abu al-Abbas as-Saffah crushed Caliph Marwan II at the Battle of Zab (Mesopotamia) in late January 750. The subsequent Abbasid Caliphate moved its capital from Damascus to Baghdad and focused its initial attention on the East.
