In 1965 Chrysostomides was appointed
lecturer in history at
Royal Holloway College. In 1983 she became
senior lecturer and in 1992
reader in Byzantine history. She retired in 1993. Throughout her career she published on Byzantine history and historiography, political theory, economy, and society. Her publications explored Byzantine women, Venetian commercial activities in the Byzantine empire, Byzantine perceptions of war and peace, and the rise of the
Ottomans. Among her major contributions were the critical edition and translation of Manuel II Palaeologus's
Funeral Oration on his Brother Theodore (1985), and the edited sources collected in
Monumenta Peloponnesiaca (1995). She also produced a number of volumes in co-operation with other scholars, including
The Letter of the Three Patriarchs to Emperor Theophilos (with Joseph Munitiz and others, 1997),
The Greek Islands and the Sea (with Charalambos Dendrinos and
Jonathan Harris, 2004),
‘Sweet Land …’: Lectures on the History and Culture of Cyprus (with Charalambos Dendrinos, 2006), and a
Catalogue of the Greek Manuscripts in Lambeth Palace Library (with
John Barron and others, 2006). Chrysostomides was also active in encouraging postgraduate students: with
Joseph Munitiz and
Athanasios Angelou, she established Britain’s first postgraduate seminar on editing Byzantine texts, and with Angelou and
Jonathan Riley-Smith, established a MA program in Late Antique and Byzantine Studies at Royal Holloway. In 1998 she became director of the Hellenic Institute at Royal Holloway. In her ten years as director she reorganized the institute, establishing it as an interdisciplinary research centre for the study of the history of Greece and Byzantium, and raising funds to establish lectureships, fellowships, graduate studentships, and
bursaries. In 1999, the Greek state bestowed on her the title of Ambassador of Hellenism in recognition of her long services to Hellenism and her contribution to Byzantine studies. ==Death==