Es graduà de Harvard el 1970 i obtingué el seu doctorat per la mateixa universitat el 1977. És casat amb Irina Andreescu-Treadgold des del 25 de setembre del 1982.
Obres
The University We Need: Reforming America's Higher Education (Nova York: Encounter Books, 2018)
The Middle Byzantine Historians (Nova York: Palgrave Macmillan, 2013)
The Early Byzantine Historians (Nova York: Palgrave Macmillan, 2007)
A Concise History of Byzantium (Nova York: Palgrave Macmillan, 2001)
A History of the Byzantine State and Society (Stanford: Stanford University Press, 1997)
Byzantium and Its Army, 284-1081 (Stanford: Stanford University Press, 1995)
The Byzantine Revival, 780-842 (Stanford: Stanford University Press, 1988)
The Byzantine State Finances in the Eighth and Ninth Centuries (Nova York: East European Monographs, 1982)
The Nature of the Bibliotheca of Photius (Washington, DC: Dumbarton Oaks, 1980)