Statistics for occurrence #1 of “Ilium” in book 1, chapter 12, section 3 of Thucydides, The Peloponnesian War:
..., and settled in the present Boeotia, the former
Cadmeis;
though there was a division of them there before, some of whom joined the
expedition to Ilium .
Twenty years later the Dorians and the Heraclids became masters of
Peloponnese; so that much had to be done
...