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Professor Sean Duffy

Prof. of Medieval Irish + Insular Histor (History)

Prof. of Medieval Irish + Insular Histor (Centre for Irish-Scottish Studies)

Seán Duffy is a graduate of Trinity College Dublin, from which he also holds an M.Litt and a Ph.D. He is a Fellow of the College, where he has lectured since 1993 and is currently Professor in Medieval History. He has supervised 20 current or completed PhDs, has been been Head of Department, a member of the Board of Trinity College Dublin, and Secretary to the Fellows. He has written or edited more than 30 books and more than 40 peer-reviewed journal articles and book-chapters, has organized 27 conferences, given over 30 keynotes or international invited lectures, and served on 10 editorial or advisory boards. Since 1998 he has been Chairman of the Friends of Medieval Dublin, an influential not-for-profit advocacy organization and is much involved in pro bono consultative and advisory work on matters relating to history and heritage, particularly with Dublin City Council. Since 1999 he has organized an annual interdisciplinary conference on medieval Dublin, the proceedings of which are published each year by Four Courts Press. In 2013 he co-founded the Trinity Medieval Ireland Symposium, held biennially, the proceedings of which are published in a new Four Courts Press series, and he also a founder and organizer of prestigious biennial James Lydon Lectures in Medieval History and Culture, the volumes of which appear in a dedicated Cambridge University Press series.
  Anglo-Irish relations   Early development of Dublin   Ireland, Scotland and wales in the Middle ages   Irish History   Medieval History   Medieval Ireland   Medieval Irish & British History   Normans   Vikings
 Medieval Dublin Series
 Battle of Clontarf Millennium
 Medieval Scottish-Irish Migration Project
 The Galloglass Project
 The Lydon Lectures 2016: Robert Bartlett, Dynasties: Family Politics in Medieval Europe (with P. Crooks, D. Ditchburn)

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Details Date
Consulting editor, History Ireland: Ireland's History Magazine 1998-date
Anonymous reviewer of book-proposals and completed manuscripts: Yale University Press, Cambridge University Press, Edinburgh University Press, Longman, Four Courts Press, etc Various
Anonymous peer-review of journal submissions: Speculum, English Historical Review, Scottish Historical Review, Irish Historical Studies, The Innes Review, Cambridge [now Cambrian] Medieval Celtic Studies, Studia Celtica, etc Various
External assessor, National University of Ireland, Post-Doctoral Fellowship in the Humanities 2014-
External reviewer, medieval history, the University of Aberdeen, Research Excellence Framework (REF) 2014
Trustee, member of Cairde Uí Fhiaich, Cardinal Tomás Ó Fiaich Memorial Library and Archive (CÓFLA), Armagh 2012-
External assessor, National University of Ireland, Travelling Studentships in the Humanities and Social Sciences 2011-
External examiner, UG & PG, medieval history, School of Divinity, History and Philosophy, University of Aberdeen 2005-8
Selection Committee, National University of Ireland, Post-Doctoral Fellowship in the Humanities 2004-
External examiner, Irish history and medieval history, Stranmillis University College, Queen's University Belfast 2002-6
External examiner, Irish, British and European history, St Mary's University College, Queen's University Belfast 2002-6
Editorial board, Cambridge University Press, James Lydon Lectures in Medieval History and Culture Series 2015-date
Keynote ('Ireland's high-kingship in the era of Brian Boru'), The era of King Brian Boru, Inaugural O'Brien Summer School, Killaloe 2016
Treasurer, Irish Historical Society 1997-2005
External examiner, medieval history and all Irish-language history papers, Department of History, NUI Galway 1998-2001
Committee, Irish Historical Society 1995-2008
Council, Military History Society of Ireland 1998-2010
Keynote ('Power and influence in medieval Ireland: the legacy of Brian Boru'), Borderlines XVIII: power and influence, 18th Annual Postgraduate Conference of Medieval and Early Modern Studies, University College Cork 2014
Steering committee, Irish-Scottish Academic Initiative (Universities of Aberdeen, Dublin, Edinburgh, Strathclyde and Queen's University Belfast) 1996-2005
Opening Lecture ('The origins of Brian Boru'), Brian Boru Program, Milkaukee Irish Fest, Milwaukee Wisconsin 2014
President, Dublin University History Society , 1994-
The John Bannerman Lecture in the History of Gaelic Scotland ('Imperium Scotorum: Ireland and Scotland in the age of Brian Boru'), University of Edinburgh 2013
Editorial board, Four Courts Press, Trinity Medieval Ireland Series 2013-date
'The vernacular among the Irish', The vernacular in medieval historical writing, Project 4: the Construction of the Past Colloquium, Centre for Medieval Studies, University of Bergen, Bergen 2012
'Hebridean Galloglass in late medieval Ireland: the Scandinavian legacy', From Gall to Gael and Galloglass, Conference of the Scottish Society for Northern Studies, Islay 2012
Keynote ('King Robert Bruce, the Galloglass and the north-west of Ireland'), The Scottish Connection, Sligo Field Club Summer Conference 2011
'Ulster, Dublin and the Irish Sea Region in the Age of Jocelin', Medieval Furness: texts and contexts, Barrow in Furness 2011
'Ireland and its neighbours in AD 1111: the Synod of Ráith Bressail in context', Department of Anglo-Saxon, Norse and Celtic Graduate Seminar, University of Cambridge 2011
'The Welsh conquest of Ireland', the Oxford Celtic Seminar, Jesus College, the University of Oxford 2009
Keynote, 'The medieval city walls of Dublin: historical context to their construction', Dublin City walls and defences conference: towards a new vision for the old city, Irish Walled Towns Network and Dublin City Council, Dublin Castle Conference Centre 2006
'King Robert Bruce the Irishman', National identity and cultural exchange in Scotland and Ireland: Irish-Scottish Academic Initiative/Leverhulme Conference, University of Edinburgh 2004
'The prehistory of the Galloglass', Military activity in the North Irish Sea World: context and response, c.1100-c.1750, University of Edinburgh 2003
'Town and crown: the kings of England and their city of Dublin', Thirteenth century England X, University of Durham 2003
Editorial board, Proceedings of the Royal Irish Academy 2012-date
'Did the Irish like the Scots?', Imagining Alba: Scotland in medieval Irish sources, AHRB Research Institute for Irish Scottish Studies, University of Aberdeen 2003
'The career of Muirchertach Ua Briain in context', Reform and renewal: Ireland and Europe in the twelfth century, International Conference to mark the 900th Anniversary of the Synod of Cashel, University College Cork 2002
'The English chronicle in the early fourteenth century: the historical context of the so-called continuation of the annals of Nicholas Trevet', 3rd International conference on the medieval chronicle, University of Utrecht, Netherlands 2002
'Emerging from the mist: Ireland and Man in the eleventh century', Mannin Revisited, Scottish Society for Northern Studies Conference, Port Erin, Isle of Man 2000
'Galleys and galloglass: naval warfare in Ireland and the Isles in the later Middle Ages', Maritime warfare in Northern Europe: technology, organisation, logistics and administration, 500 BC-1500 AD, The National Museum, Copenhagen 2000
'Tudor conquest and Gaelic collapse: Ireland in the sixteenth century', A guerra e o encontro de civilizaçóes, a partir do século XVI, 24th Congress of International Military History, Lisbon 1999
'Defining Irishness after the English invasion', Medieval Europeans: ethnic identity, cultural heritage and national perspectives in medieval Europe, University of Kent, Canterbury, and Windsor Castle 1998
'The Anglo-Norman era in Scotland and Ireland: convergence and divergence', Celebrating Columba: Irish-Scottish connections 597-1997, 1st International Conference of the Irish-Scottish Academic Initiative, University of Strathclyde, Glasgow 1997
'John and Ireland', King John: new interpretations, Department of History, University of East Anglia, Norwich 1997
'Ireland's Hastings: the Anglo-Norman conquest of Dublin', 20th Battle conference of Anglo-Norman Studies 1997
Editorial and management board, Irish Historical Studies 1995-2008
'The 1169 invasion as a turning-point in Irish-Welsh relations', Britain and Ireland 900-1300. Insular responses to medieval European change, University of Bristol 1996
'De Courcy, de Lacy and de Burgh: Ulster and England, 1177-1326', The Irish in medieval Britain, Queen Mary & Westfield College, London 1995
Editorial board, A New History of the Isle of Man 1995-2015
Advisory editorial team, Dictionary of British and Irish History, ed. R.B. Peberdy (Wiley-Blackwell, forthcoming) 2005-date
Advisor on and reader of medieval entries in The encyclopedia of Ireland, ed. Brian Lalor, Yale University Press, New Haven, Conn. and Dublin, Gill & Macmillan 2003
Advisor on medieval entries in Dictionary of Irish biography, ed. James McGuire and James, RIA and Cambridge University Press, Dublin and Cambridge, 2009
Details Date From Date To
Member, Irish Historical Society
Member, Medieval Academy of Ireland
Council, Military History Society of Ireland 1998 2010
Seán Duffy, John Montague, Kevin Mulligan and Michael O'Neill (executive editors, Ann Lynch and Conleth Manning), Dublin Castle from Fortress to Palace: Volume I. Vikings to Victorians: a History of Dublin Castle to 1850, Dublin, Government of Ireland, 2022, Book, PUBLISHED
'Part 1: The medieval period' in, editor(s)Seán Duffy, John Montague, Kevin Mulligan and Michael O'Neill (executive editors, Ann Lynch and Conleth Manning) , Dublin Castle from Fortress to Palace: Volume I. Vikings to Victorians: a History of Dublin Castle to 1850, Dublin, Government of Ireland, 2022, pp1 - 73, [Seán Duffy], Book Chapter, PUBLISHED
Seán Duffy, 'A Norman invasion? No, it was the English', Review of Plantagenet Ireland, by Robin Frame , The Irish Times, (12 March 2022), 2022, p40 , Review, PUBLISHED
'Carlingford Castle: whodunit?' in, editor(s)Terence Dooley, Mary Ann Lyons, and Salvador Ryan , The Historian as Detective: Uncovering Irish Pasts. Essays in Honour of Raymond Gillespie, Dublin, Four Courts Press, 2021, pp41 - 44, [Seán Duffy], Book Chapter, PUBLISHED
Robert Peberdy & Philip Waller (eds), A dictionary of British and Irish history, Hoboken, NJ, Wiley Blackwell, 2021, Editorial Board, PUBLISHED
Seán Duffy, Review of The Sea Kings: the Late Norse Kingdoms of Man and the Isles, by R. Andrew McDonald , Isle of Man Studies. Proceedings of the Isle of Man Natural History and Antiquarian Society, XVII, 2021, p183-4 , Review, PUBLISHED
Seán Duffy, Medieval Dublin XVIII, Dublin, Four Courts Press, 2020, 389pppp, Book, PUBLISHED
Seán Duffy, Review of Early medieval Ireland 431-1169, by Matthew Stout , Irish Literary Supplement: A Review of Irish Books, 39, (no. 2, Spring), 2020, p20-21 , Review, PUBLISHED
Seán Duffy, Medieval Dublin XVII, Dublin, Four Courts Press, 2019, 324pp, Book, PUBLISHED
History Ireland, 27, no. 3, (2019), 72p, Seán Duffy, [guest ed.], Journal, PUBLISHED

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Seán Duffy, 'Robert the Bruce and Ireland's last, Scottish high king', 2015, - 2, Miscellaneous, PUBLISHED
Seán Duffy, 'See Rome and die: the burial-place of Donnchad mac Briain', History Ireland, 22, (2), 2014, 6 - 7, Journal Article, PUBLISHED
Seán Duffy, 'Brian Boru: imperator Scotorum', History Ireland, 22, (2), 2014, 10 - 11, Journal Article, PUBLISHED
Seán Duffy, 'What happened at the Battle of Clontarf?', History Ireland, 22, (2), 2014, 30 - 33, Journal Article, PUBLISHED
Seán Duffy, ''What did Brian Boru ever do for us?', 2014, -, Notes: [The Irish Times (Battle of Clontarf Special Supplement)], Miscellaneous, PUBLISHED
Seán Duffy, 'The long Good Friday: battle began at first light and raged all day', 2014, -, Notes: [The Irish Times (Battle of Clontarf Special Supplement)], Miscellaneous, PUBLISHED
Seán Duffy, 'Three kings and a queen', 2014, -, Notes: [The Irish Times (Battle of Clontarf Special Supplement)], Miscellaneous, PUBLISHED
Seán Duffy, 'Who was Brian Boru and why does he matter?', 2014, -, Notes: [The Irish Independent (Brian Boru and the Battle of Clontarf Special Supplement)], Miscellaneous, PUBLISHED
Seán Duffy, 'The battle of Clontarf: what actually happened?' (Brian Boru and the Battle of Clontarf Special Supplement). The Irish Independent, 12 April, 2014, -, Miscellaneous, PUBLISHED
Seán Duffy, 'In memoriam: Professor James Lydon, 1928-2013', History Newsletter, Trinity College Dublin, Summer, 2013, - 12, Miscellaneous, PUBLISHED


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Award Date
Fellow, Trinity College Dublin 1998
Research Scholar, School of Celtic Studies, Dublin Institute for Advanced Studies 1990-93
Seán Duffy has published widely on Irish history generally, and medieval Ireland in particular, on Anglo-Irish relations through the ages, on the history of the Celtic countries in the medieval period, and on history and archaeology of Dublin since the Viking Age. A cornerstone of his research has been the examination of Ireland's relations with Scotland, Wales, and the Kingdom of Man and the Isles in the Middle Ages, concentrating on the period between the battle of Clontarf in 1014 (at which perhaps the greatest of Ireland's kings, Brian Boru, was slain) and the battle of Faughart in 1318 (in which Edward, brother of Robert the Bruce was killed, the man sometimes regarded as the last king of Ireland). In his work, he has developed a transnational approach, trying to uncover the various interconnections and relationships between the medieval Celtic peoples, and re-examining the great watershed moments in their affairs. He has been particularly concerned with the response of the Irish, the Scots and the Welsh to domination by England from 1066 onwards, and especially the extent to which, after the English invasion of Ireland in 1169, Ireland's experience mirrored that of Scotland and Wales. He is currently preparing a research monograph on this largely overlooked subject for Cambridge University Press. Another research approach has been to challenge the dramatic fault-line that exists in the history of Ireland whereby there are two histories, one from the Age of St Patrick up to the Anglo-Norman Invasion in 1169, the other running from then to the modern age. His conviction that this fracture is counterproductive and undermining of insight has led him to develop a specialism which, instead of beginning or ending at 1169, uses it as a midway hinge that interlocks two historiographies traditionally kept ajar. Furthermore, even the Ireland that emerged after 1169 has itself spawned two historiographies so that one is traditionally a historian of either Gaelic Ireland or of English Ireland: Seán Duffy has sought to break down this barrier, and is regarded as a historian, not of Gaelic Ireland or of English Ireland, but offering a new integrative analysis of both. He is currently researching and writing the first major History of Medieval Ireland to appear in over half a century, to be published by Yale University Press. Another of his interests lies in the history and archaeology of Dublin from the Vikings to the Early Modern period; in 1999 he established the Medieval Dublin Symposium, an annual one-day conference that has taken place in Trinity College Dublin ever since, the proceedings of which are published in a landmark Four Courts Press series. Sixteen volumes have appeared to date, amounting to 170 papers on the subject of medieval Dublin in the 17 years since the series began, more than were written in the 170 years preceding it. He is currently researching and writing a 40,000-word history of the medieval castle of Dublin, by far this country's most important building prior to Independence.