Under the early Empire, as Rome had no rival in the Mediterranean,
it was natural that the navy and naval theory should be
neglected. When Constantine the Great decided to besiege
Byzantium by sea, both he and his opponent Licinius had to create
fleets for the struggle. Even when the Vandals in Africa made
transmarine conquests and became a naval power, the Romans did
not seriously address themselves to building an efficient navy and
securing their own thalassocracy; the Vandals harried their coasts;
their expeditions against Africa failed. And even when the Vandal
power was in its decline and Belisarius set forth on his successful
expedition of conquest, his fears for the safety of his squadron in
case he should be attacked at sea allow us to suspect that the fleet
of the enemy was superior to the Roman. The conquest of Africa
secured for Justinian the undisputed command of the Mediterranean,
but he did nothing for the naval establishment. It was not till
the Saracens, aspiring to conquer all the Mediterranean coast lands,
became a naval power that the Roman Empire was forced, in a
struggle for its being, to organize an efficient fleet. This, as we saw,
was the work of Constans II., and we saw what it achieved. In
this first period (c. 650-720) the naval forces, designated as the
Karabisianoi, were laced under the command of an admiral, with
title of strategos. They consisted of two geographical divisions,
each under a drungarios: the province of the Cibyrrhaeots (probably
named from the smaller Cibyra in Pamphylia) which included
the southern coast districts of Asia Minor, and the Aegean province,
which embraced the islands and part of the west coast of Asia Minor.
The former was the more important; the marines of this province
were the hardy descendants of the pirates, whose subjugation
had taxed the resources of the Roman government in the last years
of the Republic. It was a new principle to impose the burden of
naval defence on the coast and island districts. Distinct from these
fleets, and probably organized on a different principle, was the naval
contingent stationed at Constantinople. Leo III. changed the naval
administration, abolishing the supreme command, and making the
Cibyrrhaeot and Aegean provinces separate independent themes
under strategoi. The change was due to two motives. There was
a danger lest a commander of the whole navy should become over
powerful (indicated in the political role played by the navy before
Leo’s accession); but apart from this, the general reform of Leo,
which united civil and military powers in the same hands, naturally
placed the commanders of the two branches of the navy on a new
fiooting, by making them provincial governors. In this and the
following reigns, the tendency was to neglect the fleet; the interest
of the government was concentrated on the army. For a time
this policy was prosecuted with impunity, since the Omayyad
dynasty was growing weak, and then under the Abbasids, who
transferred the capital from Damascus to Bagdad, the sea-power of
the caliphate declined. But the neglect of the fleet was avenged in
the 9th century, when Crete and Sicily were wrested from the
Empire, the loss of south Italy was imminent, and Moslem squadrons
sailed in the Adriatic,—losses and dangers which led to a
reorganization of the navy under Basil I. and Leo VI. After this
reform we find the navy consisting of two main contingents: the
imperial fleet (stationed at Constantinople), and the provincial
fleets, three in number, of (a) Cibyrrhaeot theme, (b) Aegean theme,
(c) theme of Samos. A small distinct contingent was supplied by
the Mardaites who, natives of Mt. Lebanon, had been transplanted
(partly to Pamphylia, partly to Epirus, the Ionian Islands, and
Peloponnesus). The imperial fleet seems to have consisted of
about 100 warships manned by 23,000 marines (the same men fought
and rowed); the provincial fleets of 77 warships manned by 17,000.
When the fleets acted together, the admiral in supreme command
for the time was called the “drungarios of the naval forces.” The
warships (δρόμωνες, “dromonds”) were mainly biremes, but there
were also uniremes, built for speed, called “galleys” (γαλαῖαι).
Pyrotechnic was an important department in the naval establishment;
the manufacture of the terrible explosive known as liquid
or marine fire (see Greek Fire) was carefully guarded as a state
secret.
The navy, active and efficient in the 10th century, is described by a military and therefore unprejudiced officer of the 11th as the glory of Romania. But towards the end of the 11th century it declined, the main cause being the disorganization of the naval provinces of Asia Minor, which, as we saw, was a result of the Seljuk conquest of the interior. This decline had important indirect consequences; it led to the dependence of the Empire on the Venetian navy in the struggle with the Norman power, and for this help Venice exacted commercial privileges which injured Byzantine commerce and opened the door to the preponderant influences of the Venetians in eastern trade. In the period of the Palaeologi the imperial navy, though small, was active; and the importance which it possessed for the state is illustrated by the high rank at court which the admiral (who in the 11th century had received the title of Great Duke, μέγας δούξ) then occupied; the only minister who was superior to him was the Great Domestic.
Diplomacy.—In protecting the state against the barbarians who surrounded it, diplomacy was a weapon as important in the eyes of the Byzantine government as soldiers or fortifications. The peace on the frontiers was maintained not only by strong military defences, but by more or less skilful management of the frontier peoples. In the later Empire this kind of diplomacy, which we may define as the science of managing the barbarians, was practised as a fine art; its full development was due to Justinian. Its methods fall under three general heads. (1) One people was kept in check by means of another. The imperial government fomented rivalry and hatred among them. Thus Justinian kept the Gepidae in check by the Lombards, the Kuturgurs by the Utigurs, the Huns by the Avars. (2) Subsidies were given to the peoples on the frontiers, in return for which they undertook to defend the frontier adjacent to them, and to supply fighting men when called upon to do so. The chiefs received honours and decorations. Thus the Berber chiefs on the African border received a staff of silver, encrusted with gold, a silver diadem, white cloak, embroidered tunic, &c. More important potentates were invested with a costlier dress. In these investitures precedence was carefully observed. The chiefs thus received a definite position in the Empire, and the rich robes, with the ceremony, appealed to their vanity. In some cases they were admitted to posts in the official hierarchy,—being created Patricians, Masters of soldiers, &c. They were extremely fond of such honours, and considered themselves half-Romans. Another mode of Winning influence was to marry barbarian princes to Roman wives, and rear their sons in the luxury of the palace. Dissatisfied pretenders, defeated candidates for kingship, were welcomed at Constantinople. Thus there were generally some princes, thoroughly under Byzantine influence, who at a favourable opportunity could be imposed on their compatriots. Throughout Justinian’s reign there was a constant influx of foreign potentates to Constantinople, and he overwhelmed them with attentions, pompous ceremonies and valuable presents. (3) Both these methods were already familiar to the Roman government, although Justinian employed them far more extensively and systematically than any of his predecessors. The third method was new and characteristic. The close connexion of religion and politics at Constantinople prepares us to find that Christian propaganda should go hand-in-hand with conquest, and that the missionary should co-operate with the soldier. The missionary proved an excellent agent. The typical procedure is as follows. In the land which he undertakes to convert, the missionary endeavours to gain the confidence of the king and influential persons, and makes it a special object to enlist the sympathies of the women. If the king hesitates, it is suggested that he should visit New Rome. The attraction of this idea is irresistible, and when he comes to the capital, the pomp of his reception, the honours shown him by the emperor, and the splendour of the religious ceremonies overcome his last scruples. Thenceforward imperial influence is predominant in his dominion; priests become his advisers; a bishop is consecrated, dependent on the patriarch of Constantinople; and the barbarians are transformed by the penetration of Byzantine ideas. By the application of these various means, Justinian established Roman influence in Nubia, Ethiopia and South Arabia, in the Caucasian regions, and on the coast of the Euxine. The conversion of the Lazi (of Colchis) was specially notable, and that of the Sabiri, who were politically important because they commanded the eastern pass of the Caucasus known as the Caspian Gates. It will be observed that the great prestige of the Empire was one of the conditions of the success of this policy.
The policy had, of course, its dangers, and was severely criticized by one of Justinian’s contemporaries, the historian Procopius. Concessions encouraged greater demands; the riches of the Empire were revealed. It was a system, of course, which could not be permanently successful without military power behind it, and of course it was not infallible; but in principle it was well-founded, and proved of immeasurable value. Less prejudiced writers than Procopius fully admit the far-sightedness and dexterity of the emperor in his diplomatic activity. A full account of it will be found in Diehl’s Justinien.
In the 10th century we have again the means of observing how the government conducted its foreign policy on Carefully