Drake's first book, ''In Praise of Constantine: A Historical Study and New Translation of Eusebius' Tricennial Orations'' (University of California Press), was a revision of his doctoral dissertation and examined speeches of Eusebius of Caesarea as a source for Constantine's policies. After working on a collaborative volume on a Coptic source (
Eudoxia and the Holy Sepulchre: A Constantinian Legend in Coptic (Milan: Cisalpino, 1980), he produced a series of important articles such as “Eusebius on the True Cross,”
Journal of Ecclesiastical History 36 (1985): 1-22; “Suggestions of dates in Constantine's Oration to the Saints,”
American Journal of Philology 106 (1985): 335–349; “Athanasius' first exile,”
Greek, Roman, and Byzantine Studies 27 (1986): 193–204; “What Eusebius knew: The genesis of the Vita Constantini,”
Classical Philology 83 (1988): 20–38; “Policy and belief in Constantine's Oration to the Saints,”
Studia Patristica 19 (1989): 43–51; “Constantine and Consensus,”
Church History 64 (1995) 1-15; and “Lambs into Lions: explaining early Christian intolerance”
Past &Present 153 (1996) 3-36. He followed these studies with his magisterial work
Constantine and the Bishops: The Politics of Intolerance (Baltimore: Johns Hopkins University Press, 2000). He has also co-edited
Violence in Late Antiquity with Routledge in 2006 and
The City in the Classical and Post-Classical World: Changing Contexts of Power and Identity in 2014 with Cambridge University Press. Most recently, he published
A Century of Miracles: Christians, Pagans, Jews, and the Supernatural, 312-410 in 2017 with Oxford University Press. In 2008, he retired and was awarded the status of Research Professor emeritus by the
University of California, Santa Barbara. In that year, the Harold and Kathleen Drake Fund was also established at the UCSB History Department. The Lambda chapter of Phi Beta Kappa at the
University of California, Santa Barbara created the Hal Drake Honor Key award to go "to the initiate majoring in history or the history of public policy who best demonstrates the highest ideals of Phi Beta Kappa." Some of his former students co-edited a
Festschrift to him in 2010 entitled
The Rhetoric of Power in Late Antiquity: Religion and Politics in Byzantium, Europe and the Early Islamic World (with I.B. Tauris). The
Festschrift was reprinted in a paperback version with minor corrections and revisions in 2020 (with Bloomsbury Publishing). ==Selected publications==