with their pay in their pocket, they sometimes turned on those who had
hired their arms, took their toll of youths, and finally incorporated
them in their growing empire. Like an insatiable sponge, they mopped up
the sprinklings of disconnected peoples over the fruitful floor of Asia
Minor, and swelled and prospered. But as yet the extermination of these
was not part of their programme: they absorbed the strength and manhood
of their annexations into their own soldiery, and came back for more.
They did not levy those taxes paid in the persons of soldiers for their
armies from their co-religionists, since Islam may not fight against
Islam, but by means of peaceful penetration (a policy long since
abandoned) they united scattered settlements of Turks to themselves by
marriages and the bond of a common tongue and religion.

Their expansion into Europe began in the middle of the fourteenth
century, when, as mercenaries, they fought against the Serbs, and fifty
years later they had a firm hold over Bulgaria as well. Greece was their
next prey; they penetrated Bosnia and Macedonia, and in 1453 attacked
and took Constantinople under Mohammed the Conqueror. Still true to the
policy of incorporation they continued to mop up the remainder of the
Balkan Peninsula, and at the same time consolidated themselves further
in Asia Minor. By the beginning of the seventeenth century their
expansion reached its utmost geographical limits, but already the Empire
held within it the seeds of its own decay, and by a curious irony the
force that should still keep it together was derived not from its own
strength, but from the jealousies of the European Powers among
themselves, who would willingly have dismembered it, but feared the
quarrels that would surely result from the apportionment of its
territories. The Ottoman Empire from then onwards has owed its existence
to its enemies.