St. Columcille (St. Columba) founded the abbey at Iona, (among others) and monks from there spread the Rule of St. Columba to other monasteries, like Lindesfarne, Durrow, Kells, and even to the continent, as they spread their celtic style of Christianity. Monks moved back and forth between the various places, and a fairly consistent style developed.

More discussion later, but here are links to various pinterest boards.

The Insular Art pages include links to EVERY page of the manuscripts that fit my personal criteria for analysis.

The Wikipedia list of Hiberno-Saxon illuminated manuscripts was helpful in finding these examples.