The Hiberno-Scottish mission was a series of missions and expeditions initiated by various Irish clerics and cleric-scholars who, for the most part, are not known to have acted in concert. There was no overall coordinated mission, but there were nevertheless sporadic missions initiated by Gaelic monks from Ireland and the western coast of modern-day Scotland, which contributed to the spread of Christianity and established monasteries in Britain and continental Europe during the Middle Ages. The earliest recorded Irish mission can be dated to 563 with the foundation of Iona by the Irish monk Saint Columba. Columba is said by Bede and Adamnán to have ministered to the Gaels of Dál Riada and converted the northern Pictish kingdoms. Over the next centuries more missions followed and spread through Anglo-Saxon England and the Frankish Empire. The early missions are often associated with the Christian practice known as Celtic Christianity, which was distinguished by its organizations around monasteries rather than dioceses and certain idiosyncratic traditions, but the desire to maintain a relationship with the Holy See saw their missions take on a more Roman character.
The Latin term Scotti refers to the Gaelic-speaking people of Ireland and the Irish who settled in western Scotland. In early medieval times Ireland was known not only as "Éire" but also as "Scotia", a name that the Romans used at times to refer to Ireland as well as Scotland. By the end of the 11th century it generally referred to Scotland, which had become Gaelicised by settlers from Ireland, and from where the name Scotland derives. The Romans also gave Ireland the name "Hibernia". Thus, the "Scots" missionaries who were so influential in the early Church history of Germany included men from both modern countries Ireland and Scotland.