Alexander John Graham, ancient historian: born Lowestoft, Suffolk 9 March 1930; Assistant Lecturer in Classics, Bedford College, London 1955-57; Assistant Lecturer in Ancient History, Manchester University 1957-59, Lecturer 1959-70, Senior Lecturer 1970-77; Professor of Classical Studies and Allen Memorial Professor in Greek, University of Pennsylvania 1977-95 (Emeritus), Chairman, Department of Classical Studies 1982-95; married 1963 Jenny Fitter (two sons); died Cambridge 26 December 2005.

A. J. Graham was one of the foremost authorities on the colonisation movement in the ancient Greek world. His pioneering first book, Colony and Mother City in Ancient Greece (1964), went through a second edition in 1983 and is still in print. His Collected Papers on Greek Colonization, gathering all the papers published by him on the subject over 40 years, appeared in 2001.

Alexander John Graham was born in 1930 into an old Quaker family in Lowestoft, Suffolk, where his father, Michael Graham, was Director of HM Fisheries Laboratory and an author of books on ecology, agriculture, and human behaviour. Conforming to family tradition, like his father before him and his sons after him, he was educated at Bootham, the Quaker school in Yorkshire, where he counted Victor Ehrenberg and John O. Burtt among his teachers. These were the men who gave his life the decisive direction to a scholarly career in Classics and Ancient History.

After National Service in the Army, Graham went up to King's College, Cambridge, on a scholarship, in 1949, and after graduating with distinction in Ancient History worked for a PhD under the watchful eye of Professor Sir Frank Adcock at Cambridge, also spending time at the University of Munich and at the British School at Athens.

In 1956, while he was still assistant lecturer at Bedford College, London, he was awarded the Cromer Greek Prize of the British Academy for his essay on the authenticity of the foundation decree of Cyrene. He developed this essay into Colony and Mother City in Ancient Greece.

After two years at Bedford College, in 1957 Graham accepted a teaching post at Manchester University, where he stayed for 20 years. There, despite a demanding teaching load, he produced 31 articles and reviews, establishing his standing as one of the leading historians of Greek colonisation in the Mediterranean, and also adding an expertise in Roman imperial history, especially under the Severi.

He contributed articles on "Colonization, Greek", "City-Founders", "Cleruchs" and "Cyrene" to the second, 1970 edition of The Oxford Classical Dictionary and essays on colonisation to the new, second edition Cambridge Ancient History. And he co-edited a volume, Polis und Imperium, in honour of his teacher Victor Ehrenberg in 1965.

Graham's most productive period began in 1977, when he accepted a call to the University of Pennsylvania as Professor of Classical Studies, and when the modern authority on Greek colonisation became himself - a Quaker by origin and upbringing - an oikistes (coloniser) in what had been colonised three centuries earlier by British Quakers.

This appointment presented for Graham an opportunity he had long coveted. Membership in a department of Classical Studies afforded him more of an opportunity to teach and study classical texts in the original languages, and the presence of a distinguished historian in what had been primarily a department of languages and literature gave a tremendous impetus to the Graduate Group of Ancient History, recently established by Graham's predecessor, Professor Michael H. Jameson. It enabled Graham to give full rein to his interest not merely in Greek and Roman political history, but also in its religious and cultural dimensions, and in its relations to other ancient cultures. Students were required to choose dissertation subjects that spanned at least two ancient cultures (Greek, Roman, Hebrew, Egyptian, Hittite, Assyrian etc, in any combination and with proficiency in the languages, literatures, and religions of each).

John Graham's interests were tailor-made for this kind of programme. In both his teaching and his numerous publications he could draw on his expertise in the interpretation of literary texts and inscriptions, as well as on his profound knowledge of archaeology and of the social, political, and religious institutions of the lands penetrated by the Greeks and the Romans.

His sharp historical acumen, his intellectual clarity and his compassionate nature found resonance both with students and colleagues. He inspired dissertations on a great range of subjects - including studies of the role of the founder and of religion in the foundation of Greek colonies; of government in colonial states; of Persian coins; of the defences of Attica; of Attic phratries; of diplomatic terminology in the Hellenistic Age; of the chronology of Delphi; of the history of Miletus; and of textual problems in Thucydides.

Despite his stubborn refusal to surrender to the use of e-mail, few students and colleagues regarded that as an obstacle to staying in touch with him, even after he withdrew to his native England upon his retirement in 1995.

A number of his former students expressed their esteem by publishing, under the editorship of Vanessa B. Gorman and Eric W. Robinson, a collection of 18 papers in his honour, Oikistes: studies in constitutions, colonies, and military power in the ancient world (2002).