She later was promoted to the chair of Greek and the development of moral and political thought at the Collège de France — the first woman nominated to this prestigious institution.

She published dozens of works on Greek philosophy, language and literature but her lifelong passion was Thucydides, the historian of the Peloponnesian War.

[6] Her position in the Académie française enabled her to mount a defence of classical languages and literary culture, which she stated “may well be as endangered as the fauna of the oceans or the water of our rivers”.

[7] She was horrified by the 1988 vote to simplify aspects of the French language in primary schools and in 1992 she founded an Association for the Defence of Literary Studies.

[10][11] De Romilly's two monographs on the ancient Greek historian Thucydides have been credited with "alter[ing] the landscape of Thucydidean scholarship"[12] and "the beginning of a new era".

[15][16] De Romilly believed that Thucydides's intelligent, reflective approach held lessons relevant to the Europe of today.