A History of Sea Power

by William Oliver Stevens; Allan F. Westcott

The eastern line of invasion was undertaken first in the year 717. A fleet of warships and transports to the number of 1800 sailed to the Hellespont, carrying about 80,000 troops, while a great army collected at Tarsus and marched overland toward the same destination. Meanwhile two more fleets were being prepared in the ports of Africa and Egypt, and a third army was being collected to reënforce the first expedition. This army was to be under the personal command of the Caliph himself. The third attack on the Christian capital was intended to be the supreme effort.

Fortunately, the ruler of Constantinople at this hour of peril was a man of ability and energy, Leo III; but the empire had sunk so low as a result of the misrule of his predecessors that his authority scarcely extended beyond the shores of the Sea of Marmora, and his resources were at a low ebb. The navy on which so much depended was brought to a high point of efficiency, but it was so inferior in numbers to the Saracen armada that he dared not attempt even a defense of the Dardanelles.

For the Arabs all went well at first. Unopposed they transported a part of their army to the European shore, moved toward Constantinople and invested it by land and sea. One detachment was sent to cover Adrianople, which was occupied by a Christian garrison; the rest of the force concentrated on the capital itself.

Meanwhile the Christian fleet lay anchored in the shelter of the Golden Horn, protected by a boom of chains and logs. As the Saracen ships came up to occupy the straits above the city they fell into confusion in trying to stem the rapid current. Seeing his opportunity, the emperor ordered the boom opened, and leading the way in his flagship, he fell upon the huddle of Saracen vessels in the channel. The latter could make little resistance, and before the main body of the fleet could work up to the rescue, the Christians had destroyed twenty and taken a number of prizes back to the Horn. Again Greek fire had proved its deadly efficacy. Elated with this success, Leo ordered the boom opened wide and, lying in battle order at the mouth of the Horn, he challenged the Arab fleet to attack. But such was the terror inspired by Greek fire that the Grand Vizier, in spite of his enormous superiority in numbers, declined to close. Instead he withdrew his dromons out of the Bosphorus and thereafter followed the less risky policy of a blockade. This initial success of the Christian fleet had the important effect of leaving open the sea route to the Black Sea, through which supplies could still reach the beleaguered city.

The Arabs then sat down to wear out the defenders by a protracted siege on land and sea. In the spring of 718 the new army and the two new fleets arrived on the scene. One of the latter succeeded, probably by night, in passing through the Bosphorus and closing the last inlet to the city. The situation for the defenders became desperate. Many of the men serving on these new fleets, however, were Christians. These took every opportunity to desert, and gave important information to the emperor as to the disposition of the Arab ships. Acting on this knowledge, Leo took his fleet out from the shelter of the boom and moved up the straits against the African and Egyptian squadrons that were blockading the northern exit. The deserters guided him to where these squadrons lay, at anchor and unprepared for action. What followed was a massacre rather than a battle. The Christian members of the crews deserted wholesale and turned upon their Moslem officers. Ship after ship was rammed by the Christian dromons or set on fire by the terrible substance which every Arab regarded with superstitious dread. Some were driven ashore, others captured, many more sunk or burnt to the water's edge. Of a total of nearly 800 vessels practically nothing was left.

Leo followed up this spectacular naval victory by transporting a force from the garrison of the city to the opposite shore of the Bosphorus, attacking the army encamped there and driving it in rout. Meanwhile the Bulgarian chieftain had responded to Leo's appeal and, relieving the siege of Adrianople, beat back the Saracen army at that point with great slaughter. The fugitives of that army served to throw into panic the troops encamped round the walls of Constantinople, already demoralized by disease, the death of their leaders, and the annihilation of the African and Egyptian fleets in the Bosphorus.

The great retreat began. The Arab soldiers started back through Asia Minor, but only 30,000 out of the original force of 180,000 lived to reach Tarsus. The fleet set sail for the Ægean, and as in the similar retreat of a half century before, the Arabs were overwhelmed by a storm with terrible losses. The Christian ships picked off many survivors, and the Christians of the islands destroyed others that sought shelter in any port. It is said that out of the original armada of 1800 vessels only five returned to Syria! Thus the third and supreme effort of the Saracen ended in one of the greatest military disasters in history.

The service of the Christian fleet in the salvation of the empire at this time is thus summarized by a historian:

"The fleet won most of the credit for the fine defense; it invariably fought with admirable readiness and discipline, and was handled in the most masterful manner. It checked the establishment of a naval blockade at the very outset, and broke it when it was temporarily formed in 718; it enabled the army to operate at will on either shore of the Bosphorus, and it followed up the retreating Saracens and completed the ruin of the great armament."[1]

[Footnote 1: The Byzantine Empire, Foard, p. 170.]