Throughout the medieval period there were close connections between Ireland and Scotland, largely because many areas of Scotland shared a common Gaelic culture with Ireland. This led to a considerable degree of cultural interaction, although in general Irish culture was more influential in Scotland than vice versa. The peoples of medieval Scotland held a place in the geographical consciousness of the Irish, as the frequent journeys in tales of Irish heroes to Dal Riata, Pictland, and Alba indicate, but there are fewer clear examples where the Irish were influenced by those in Scotland.
In the Early Medieval period much of the influence probably came through Dal Riata in western Scotland, which had important ecclesiastical establishments among the Picts and Northumbrians. It is likely that Dal Riata was a crucial intermediary in the seventh-century development of the Hiberno-Saxon art style shared by Dal Riata, Pictland, Northumbria, and Ireland, combining artistic attributes from each region. Iona, founded by the Irish Columba, seems to have been particularly significant. The Iona Chronicle, kept from at least 660 to 740, forms a significant element in all the surviving Irish chronicles of the period, and Adomnan’s Life of St Columba was probably a model for later Irish saints’ lives, such as the late eighth-century Life of St Cainnech. The descriptions of rulers as "kings of Ireland" in both of these Iona texts are the first explicit references to the concept of a high-kingship of Ireland.
Later in the Middle Ages a number of historical texts from Scotland were transmitted to Ireland, then copied and sometimes adapted in Ireland so that they became part of the Irish historical tradition. The clearest case of this is Lebor Bretnach, a Gaelic version of the Latin Historia Brittonum, or "The History of the Britons." This text was produced in lowland Scotland in the late eleventh century specifically for an Irish audience, and survives in a number of Irish manuscripts. Other Scottish texts are found in Irish manuscripts, including the tenth-century Miniugud Senchasa Fher nAlban, whereas versions of the Pictish king-list occur in Lebor Cabala or accompany Lebor Bretnach. In some cases, such as the late-eleventh century Duan Albanach, the genealogy of the rulers of Moray and the Alba king-lists, Scottish materials were adapted for the creation of texts in Ireland. The effect of these Scottish texts on Irish historical thinking is at present unclear, but they may reflect an increased interest in Scottish affairs caused by the dominance of Gaelic culture in formerly Pictish areas and the prestige of the expansionist Gaelic kings of Alba.
From the twelfth century onward lowland Scotland became increasingly English-speaking, so that there was less cultural interaction with Ireland. However, the Highlands and the Isles of Scotland maintained a high degree of contact with Ireland, with bards often travelling between Ireland and Scotland and maintaining a single poetic culture, but the degree to which Ireland was influenced by Scotland in terms of literature during this time is uncertain.
