By AD 900, the western seaways were controlled by the Vikings – the Norsemen. Christian Norse settlers joined the mixed population of Whithorn, and made a distinctive contribution to its melting-pot of cultural influences.
Whithorn remained a focus of ecclesiastical power and it was in this period that the distinctive development
in sculpture took place. The new tradition emerged in the mid-900s, represented by the carved crosses of the Whithorn School. The survival of so many sculptured crosses indicates that Christianity continued to flourish in the region. The new ruling class buried their dead beside the old shrine of St Ninian. Among the carved stones found here there were at least 20 small crosses, used as headstones for graves dating from the Viking period. Similar memorials have been found at St Ninian’s Cave
Archaeological excavations in 1984 revealed a range of evidence from this period, including a stake-built house similar to those found in Viking York and Dublin. This was interpreted as part of a secular settlement on the edge of the monastic precinct. Excavations also revealed extraordinary levels of craft working, with Whithorn as part of a vigorous trade network.
The Viking rule of Galloway seems to have come to an end around 1100. By the 1120s Galloway dues were being paid to the Scottish king, Alexander I. A new age began for Whithorn, in which the feudal lords of Galloway would appoint bishops of their choosing.