As we have seen, a strong vein of mutual toleration characterised relations
between the Byzantine and the Turkish ruling families in the twelfth and
thirteenth centuries. Individual careerists and exiles moved between their
respective courts in quest of advancement or asylum, and the Seljuq sultan
generally showed little inclination to try and take full advantage of those
occasions when the Byzantine administration in western AsiaMinor was in
disarray. It was, above all, the coming of theMongols – their erosion of the
power of the Rum sultanate to the advantage of individual warlords and
their savage measures against local populations in eastern AsiaMinor – that
prompted the migration of sizable numbers of Turks westwards, swamping
the Byzantine defences. Andronikos II’s administrative deficiencies and
general disregard for Asia Minor further aggravated the situation. But, as
so often in Byzantine history, the mainsprings of action lay far beyond the
empire’s borders or means of control.
The Turkish conquest of 1302–5 was more than a simple nomadic invasion,
seeing that sedentary and transhumant elements had long co-existed
in the border zone. After the Turks’ conquest of what was left of Byzantine
Asia Minor, not only did nomads settle in their newly conquered lands,
but these lands also soon became the target of Muslim immigration from
the depths of central and eastern Asia Minor, leaving the dwindling Greek
communities little chance of survival. This rapid change in the ethnic balance
meant there was no hope of Byzantium recovering its lost provinces
in western Asia Minor. When the Catalans finally departed, they left an
empire that was devastated and bankrupt. Byzantium’s former possessions
in western Anatolia were divided between various Turkish warlords, who
managed to establish successful principalities along the coasts of the Aegean
and the Sea of Marmara. One such Bithynian beylik – that of Osman –
would become the cradle of a new formation: the Ottoman Turks.