Although these two books are rather different in scope and ambition, they share a common interest in early medieval travellers between Ireland and northern Britain, and are in many ways complementary. Oisín Plumb is concerned principally with Pictish and northern British travellers to Ireland, particularly between the fifth and the eighth centuries, while Fiona Edmonds examines travel and other connections between Ireland (and western Scotland) and the Northumbrian kingdom (including Dumfries and Galloway) between the eighth and twelfth centuries. Both grapple with problems in using the surviving written sources and church dedications, but Edmonds ranges much more widely to include evidence from place-names, onomastics, language and material culture that can extend and challenge the inferences of the textual material. A picture of the Irish Sea as a facilitator of relationships in the early middle ages, rather than a barrier, emerges from the two studies, but unpicking the layers of influence is not straightforward, and some connections and periods of influence are more apparent than others that may be suspected but are harder to illustrate definitively.

Oisín Plumb's book derives from his recent doctoral thesis and it has the clearly defined parameters and sharply focused discussion that one would expect from such doctoral studies. Some of the sources he examines are extremely well known, and Plumb struggles to find anything new to say about the origins of St Patrick or the problematical identity, or rather identities, of Uinniau/Findbar/Finnian/Ninian, but his reviews of the debates are clearly presented and useful. Other sources are less well known, including a poem from the Book of Leinster genealogies of the saints concerning seven allegedly Pictish ‘brothers’ who came to Ireland in the late seventh or early eighth centuries. Plumb points to how records of Pictish kings taking refuge in Columban and other Irish areas mirror the reputed travels of ecclesiastics, including faint but persistent traces of a particular connection between the far northern Pictish zone and Ireland. An interesting concluding section looks at how what he calls the migration narrative of early ecclesiastics developed over time. In the Irish church a connection with British ecclesiastics became an Edenic desiderata. By the twelfth century Patrick had acquired several sisters who apparently intermarried with politically important Irish families and/or founded their own churches. In the new kingdom of Alba that had replaced the Pictish kingdom by the tenth century, early medieval origins were also desirable, and Pictish kings might be recorded as donors of churches, but it was Gaelic origins that were preferred for churchmen. Although Pictish saints were included in the Aberdeen breviary they are not identified as such, and in the Book of Deer the Pictish saint Drostan was claimed as a disciple of Columba and given a Gaelic patronym. The activities of many Irish saints were transposed to Scotland from Ireland, giving an illusion of Scottish Gaelic rather than Irish origins. Plumb concludes that Pictish and British interactions with Ireland were undoubtedly important between the fifth and seventh centuries, but that extreme care has to be taken in identifying genuine early references in later migration myths.

Fiona Edmonds, on the other hand, has the task of reducing down to manageable limits her enviable expertise in a range of disciplines built up over many years of research. A bibliography in excess of sixty pages is an eloquent testimony to the reach and detail of her studies. Yet the book is never less than highly readable, and her discussions are both concise and clear with her own conclusions and the reasons for them clearly signalled. This book is going to be essential reading for early medieval insular scholars for many years to come, and a short review cannot do justice to its many original interpretations. One of Edmonds's essential arguments is that there were ‘enduring and varied links between Gaeldom and the Northumbrian kingdom’. Those between Ireland and Iona with Northumbria described by Bede are relatively well known. Edmonds shows that the synod of Whitby changed, but did not decisively disrupt them, nor did they end with the fall of the Northumbrian kingdom in the ninth century which instead led to an acceleration and diversification of Gaelic influence. The Viking kingdom of York and Dublin was able to utilise well-established trading routes and political connections, and these persisted after the last Scandinavian king of York was expelled in 954. The distribution of Gaelic personal names in Domesday Book coincides with the major communication routes between York and Dublin which are also marked out by distribution plots of much earlier artefacts.

Although she considers the relations of the whole of the Northumbrian kingdom with Gaeldom, Edmonds's main focus is on the areas bordering the Irish Sea, either side of the Solway Firth. This is the part of the Northumbrian kingdom that was ‘last in and first out’ and is poorly represented in written sources, so that it often receives minimal treatment in studies of Northumbria as a whole. By drawing on Irish sources that are not always well known to Anglo-Saxon historians, and a range of linguistic and material evidence, Edmonds is able to flesh out a convincing history for the region. The Isle of Man is seen as a key link between this area and the Gaelic world, and competition to control it and the Irish sea routes emerges as a major focus of both Northumbrian and Viking warfare. The names and scripts on Manx sculpture help testify to its varied geographical and linguistic links in the absence of any local written sources. Movement of peoples throughout the Irish Sea region was a constant even if more intensified in some periods. Edmonds in particular stresses the importance of the Gaelic element in the Viking groups active in England and Ireland, including the Gaill-Goidil who, it is now believed, were responsible for the spread of Gaelic into the Solway region in the eleventh century from their original base on the Clyde.

The two books therefore share a number of preoccupations and problems. Not the least of these is the terminology used to describe languages and peoples from different eras and areas. Both authors are concerned with interpreting early medieval labels and deciding what ones to use today, and are well aware that early medieval terminologies were not necessarily as precise or consistent as modern scholars would like them to be. The shift of Scotti by the tenth century from designating speakers of Gaelic from Ireland and the Hebrides in the fifth and sixth centuries to the inhabitants of the new kingdom of Alba based on the former Pictish kingdom in eastern Scotland is relatively well known, but did a twelfth-century writer use Scotti in the contemporary sense or might they have had access to a lost text from an earlier period that retained the usage of that time? Edmonds's decision to refer to ‘Gaelic’ rather than ‘Irish’ helps to avoid confusing past language use with modern geographical ethnicities.

Fiona Edmonds also has to grapple with problems concerning the designation of various Viking groups that operated on both sides of the Irish Sea. Early medieval writers based in Ireland and England did not necessarily refer to the same groups in the same way and the constituencies of the various armies were not constant. Although it was their Scandinavian-ness that impressed itself on contemporaries — something that no doubt originally manifested itself in language, dress and behaviour — the Irish-based Vikings eventually emerged as Gaelic speakers and were closely embroiled in the political structures of Ireland and the Hebrides. She suggests that women had a major part to play in the transformation. Although archaeological and D.N.A. evidence suggest that some women did travel from Scandinavia with the armies, written evidence records marriages of women from politically important Irish families with Scandinavian leaders with the result that subsequent generations would have both Irish and Scandinavian kin. As migration from Scandinavia slowed, Irish links and kinship presumably became more dominant.

The interpretation recalls the evidence Plumb discusses for an earlier period of possible British migration to Ireland preserved in the records of the marriages of St Patrick's presumed sisters into prominent Irish families. Although one is rightly suspicious of a proliferation of Patrician siblings, such myths may nevertheless retain some remembrance of migrations from northern Britain to Ireland following the collapse of the Roman empire. The role of Irish women as wives and slaves in the settling of Iceland and the Faroes in Norse sagas might seem a comparable plot device, but seems to be confirmed by recent study of the mitochondrial D.N.A. of their modern populations. Fiona Edmonds ends by reminding us that the topic of early medieval interactions over the Irish Sea is far from closed with new material coming to light all the time that is likely to lead to further modifications. As she was writing exciting new information was coming out about the recent find known as the Galloway hoard that seems to exemplify the interactions that are at the heart of her study, but the integration of that material into her comprehensive thesis will have to wait for another time.