Celtic knot interlacing shows up in Irish monuments, stone crosses, jewelry, and illuminated manuscripts. This familiar interlaced art peaked in Ireland around the 7th-9th centuries, during the Celtic Revival.
The basis for this design collection is the Lindisfarne cross, which marks the site where the Lindisfarne Gospels were illuminated.
Monks illuminated the Lindisfarne manuscripts around 700 AD in a monastery off the coast of Northumberland. The style has been described as Hiberno-Saxon, or insular art. Similar illumination of Christian gospels is seen in the Book of Durrow (ca.700 CE) and the Book of Kells (ca.800 CE), combining western calligraphy with insular decoration.
I have drawn a pattern based on the stone Lindisfarne Cross, and repeated it digitally in many variations of color and arrangement. Comparable celtic knot combinations are found in the St. Patrick, Farr Stone, Colum Cille, Ruthwell, and the Claddagh Crosses. Celtic interlacing shows a sense of continuity, and appreciation for eternal aspects of life.
More information on symbolic meaning can be found at celtarts.com.