By the late summer of 1084 Robert Guiscard must have felt
finally ready to resume his Balkan campaign after a three-year hiatus. He had
crushed the latest revolt of his Apulian nobles at Cannae, sent the German
emperor Henry IV scampering back north of the Alps and rescued his liege lord
Pope Gregory VII from Rome, albeit after a savage sacking of the city. The
appearance of his son Bohemond in Salerno must, however, have dampened any
ephemeral euphoria and disabused him of the notion of an easy expedition.
Thanks in large measure to the Greco-Venetian fleet, much of what had been
gained before his untimely return to Italy had been lost.
Guiscard’s naval capability had never recovered from the
defeat it had suffered at the hands of the Venetians off Pallia Point north of
Durazzo in July 1081. As a result, his forces had lost freedom of movement on
the sea. Anna Comnena explained: `The Roman and Venetian fleets, tirelessly
patrolling the straits [the Strait of Otranto between Apulia and modern
Albania], prevented reinforcements crossing from Lombardy [Italy] and delivery
of necessary supplies to him [Guiscard] from that area was impeded.’ This meant
that Bohemond’s efforts to continue the Balkan campaign in his father’s absence
were doomed from the start. He soldiered on nonetheless, defeating Alexios at
Ioannina and again near Ochrid. Bohemond then marched into Thessaly where he
took Trikkala and laid siege to Larissa. It was there that the young
Hauteville, short on supplies and lacking funds to pay his exhausted troops,
bogged down. Alexios, at last seeing the futility of head-on encounters with
the Norman heavy cavalry, shifted tactics. He suborned many of Bohemond’s
knights with the compensation Guiscard’s son could no longer provide without
help from across the Adriatic. The campaign soon crumbled, leaving Bohemond no
option but to make his way back to Italy for reinforcement and replenishment.
Meanwhile, the Venetians, urged on by Alexios and supported
by the Greek fleet under Michael Maurex, prosecuted the war at sea
unchallenged. They recaptured Durazzo in the summer of 1083, then reclaimed all
of Corfu, excluding the Norman-held citadel of Kassiopi on the northeastern
promontory of the island. By the autumn Alexios had recaptured Kastoria. Aside
from Avlona and Kassiopi, almost nothing of Greece remained in Norman hands.
And those few Norman forces still loyal to Guiscard had been rendered
perilously isolated and susceptible to seaborne attack. Robert must have
suffered no illusions: if his Byzantine aspirations were to be realized, he
would have to wrench mastery of the lower Adriatic from the Venetians.
Preparations for his second Balkan expedition were informed by that knowledge.
Accordingly, Robert amassed at Taranto in the fall of 1084
what Lupus Protospatarius called `a huge gathering of ships and an innumerable army
of men’. There is some controversy about the exact numbers involved. Modern
scholars such as Ferdinand Chalandon have estimated that Guiscard’s fleet
consisted of around 150 ships, but the only contemporary source to offer a
precise figure was William of Apulia, who claimed that the armada comprised 120
armed ships (`armatis centum viginti navibus’) along with an unspecified number
of `transport vessels filled with horses, provisions and arms’. The great
Italian maritime historian Camillo Manfroni regards even this estimate as an
exaggeration, because the number of galleys alone would have required 12,000
men just to crew them. Nonetheless, given Robert’s prior experience with
Venetian naval power, the duke probably assembled a fleet of warships much
larger than the one he had employed on the initial Balkan expedition three
years before.
It was late in the sailing season – perhaps early September
– before Robert was ready, so, instead of crossing from Otranto, the port which
offered the shortest passage to Corfu, both Lupus Protospatarius and William of
Apulia reported that Robert repositioned the fleet to Brindisi because it
provided better shelter from autumn storms. He obviously had no wish to repeat
the horrendous experience of Glossa Point in 1081, when his fleet was very
nearly demolished in its entirety by a terrible tempest. The duke dispatched an
advance squadron under his sons Roger Borsa and Guy to secure Avlona once
again. Guiscard himself proceeded with sons Bohemond and Robert to Butrinto on
the Balkan mainland, just opposite the northeastern coast of Corfu, with the
intention of relieving his garrison at Kassiopi. Roger and Guy rendezvoused
with him there, but fierce autumn weather forced the entire expedition to
hunker down for nearly two months. In the meantime Alexios, having learned of
Guiscard’s movements, directed the Greco-Venetian fleet to counter the
anticipated assault on Corfu. Anna Comnena reported that these ships anchored
at the harbour of Passaron, believed to be on the coast of Epirus somewhere to
the south of Butrinto. Thus Robert was probably aware of their presence in the
vicinity.
Sometime in November, when the weather finally cleared,
Guiscard seized the initiative by crossing the Strait of Corfu to Kassiopi with
his entire fleet. Soon thereafter the Venetians moved to engage. The two fleets
apparently clashed in the harbour of Kassiopi because Anna Comnena says the
battle `took place at close quarters’. In such a battle of limited manoeuvring,
the advantage must have been with the taller Venetian vessels, which were able
to rain missiles down at will upon Guiscard’s galleys with their low freeboard.
William of Apulia called them `triremes’, but this was clearly a classicized
reference to what were probably bireme galeas. `They [the Venetians] showered
arrows from on high on their enemies and threatened them with heavy iron
weights,’ he recounted. The effect must have been devastating. `In the ship
carrying Roger during this battle scarcely a man could be found unwounded,’
added William. The Normans took a terrible beating but survived the encounter
only to be attacked again three days later with much the same result.
After this second triumph the Venetians returned to the
harbour at Passaron, convinced that Guiscard had been so thoroughly vanquished
that he no longer posed a threat. They even went so far as to send their light
galleys home for the winter, while relocating their larger vessels to the port
of Kerkyra midway down the east coast of Corfu. Such overconfidence was to
prove catastrophic. The Venetians had woefully misjudged their adversary. Anna
Comnena explained: `Robert was a determined champion of his own designs and
prejudices, absolutely resolved never to give up a decision once taken: in a
word indomitable.’ Guiscard learned from a defector named Pietro Contarini that
the Venetians were, in effect, standing down for the winter, so he hastily
prepared his fleet for a surprise attack. He divided the twenty galeas that apparently
remained to him into four squadrons of five ships each: one each under his sons
Roger, Bohemond and Robert, keeping the last one for himself.
When Robert’s squadrons suddenly came upon the Venetians in
the port of Kerkyra, Anna Comnena said, `The latter were astounded by the
unexpectedness of it, but lost no time in linking their bigger vessels with
iron chains in the port of Corfu [Kerkyra], with the smaller ships inside this
compact circle [the so-called `sea harbour’].’ While the smaller Venetian
galleys had been sent home, the Greek galleys of Maurex apparently remained in
support, so Guiscard ordered Roger to separate them from the Venetian flotilla.
William of Apulia identified the Greek vessels as chelandia. Since Roger’s
ships were probably galeas, which theoretically would have been larger and
faster, his squadron would have had the advantage despite the superior number
of Greek ships. In any event, the young Hauteville succeeded in chasing them
off, leaving the Venetian `sea harbour’, composed of nine large vessels, to
face the assault of the other Norman galeas on its own.
Anna Comnena describes this `sea harbour’ as a `compact
circle’, but in point of fact it was probably what Camillo Manfroni more
accurately characterized as a semicircle, i. e., the classic crescent fighting
formation prescribed by the Byzantine emperor Leo VI in Constitution XIX of his
Taktika on naval warfare. Hence, it is likely that Robert would have employed
something similar to the tactic Leo VI recommended for combating such a
crescent defensive posture: attacking the flanks with two five-ship squadrons
while striking the centre with the third. As fortune would have it, the
Venetian floating fortress was especially vulnerable to this sort of assault.
According to Anna Comnena, the Venetians had evidently consumed most of the
supplies carried by these ships so that the vessels were riding high in the
water, making them dangerously top- heavy. Consequently, when the Norman
squadrons engaged the ends of the Venetian formation, calamity befell these
vessels. Anna described what happened in lurid detail: `The latter, because
they had no cargo, floated on the surface as if buoyed by the waves (the water
did not even reach the second line), so that when the men rushed to one side to
oppose the enemy, the boats immediately sank.’
Informed conjecture has it then that the ships on the horns
of the crescent capsized, quite conceivably dragging down the vessels chained
to them, one after the other. Of the nine vessels in the Venetian floating
fortress, William of Apulia reported that seven were sunk and the remaining two
were effortlessly captured. Most of the Venetian combatants who had the
misfortune of tumbling into the sea probably did not survive – it was late
November and the water temperature would have made hypothermia a killer. This
sort of scenario would account for the appalling loss of life suffered by the
Venetians. Anna Comnena lamented that as many as 13,000 were drowned. Lupus
Protospatarius claimed a more modest 5,000 mortalities among the Venetians. William
of Apulia did not give an estimate of enemy losses, but reported that the
Normans took 2,500 captives, whom Anna Comnena insisted fared poorly in
Robert’s care. `Many of the prisoners were treated with hideous savagery: some
were blinded, others had their noses cut off, others lost hands or feet or
both.’
