Without, however, seeking further to discover the reasons for the internal divisions and the consequent civil wars, their existence and baneful effects are the most manifest, though not the most important, of the evils which weakened the Empire.
Divisions of race in Balkan peninsula.
The second fact associated with the mischief caused by the Latin conquest, which contributed to the decay of the empire, is that such conquest prevented the assimilation of the various peoples occupying the Balkan peninsula. Even at the best period of the empire that population had always been strangely diversified. Albanians and Slavs had been there from very early times, side by side with Greeks and the race known as Wallachs, each of the four races having a distinct language.
The influence of good administration and the strong hand of the central power kept these races in order. They had the usual tendency to hostility one towards the other, but until the Latin conquest good government and the Greek language, that of the Church and administration, were always a force tending to break down the boundaries between them and to incorporate isolated sections in the Greek-speaking community. But at all times their mutual jealousies constituted, as indeed they do now, the most difficult factor in the problem of the government of the Balkan peninsula.[168]
This difficulty had been enormously increased by the Latin conquest. The populations were harassed everywhere by native rebellions and by foreign invaders: Greek pretenders to the empire who refused to recognise the crusading kings: crusading knights who settled in Greece after the expulsion of Baldwin: adventurous soldiers of fortune from Italy: freebooters from the Catalan Grand Company: Venetians and Turks: and lastly by dissensions between the emperors themselves, the most hurtful of which were between Cantacuzenus and John.
The various invaders found their task easier from the hostility which existed between the various groups. Racial animosity was fostered by inducements held out by the newcomers to one group to join them in attacking another. These troubles destroyed the work of assimilation which had been going on for centuries. Communities now of Greeks, now of Slavs, were driven from the localities they had occupied for long periods, and the constant movement left the Balkan peninsula with its various races intermingled in strange confusion. To adopt chemical nomenclature, hundreds of villages were mechanically mixed with those of other races but never chemically combined. There were Slav villages in the neighbourhood of Athens itself, Albanians in Macedonia: Greeks, Serbians, and Bulgarians largely replaced the Latin race of that province, which in the times of the Crusades was known as Wallachia Proper. Language and race had taken the place of subjection to the empire as a bond of union, and as the Turks gradually pressed forward their advances into the interior, literally from every side, they found the conquest of these isolated and generally hostile communities greatly facilitated by the disunion existing among them.
Throughout Macedonia, Thessaly, Epirus, and Greece the boundaries were changed oftener even than allegiance, and though the Greek element predominated in the south and along the coast as far as Salonica and around the coasts of the Aegean and the Marmora, other communities were interspersed among them in great numbers.
The subjugation of the Macedonian Serbs and the South Bulgarians can be roughly stated as having been accomplished at the battle on the Maritza. The defeat of the Serbians and Bulgarians was a harder task. But Serbia and Bulgaria were the two portions of the Balkan peninsula where the people were almost all of the same race and could organise themselves for defence. No such organisation was possible south of their territory.
System of Turkish conquests.