South African scholar Brenda Sullivan comments:
“This symbol has many names. It has been called the five-fold bond, the tree of life enclosed within the circle of eternity, and more commonly, the Celtic cross. Well, the Celts may claim pride of name, but this most ancient symbol has been associated with the isangomas [medicine people] of Africa for millennia, and is still one of Africa’s most powerful signs of protection and communication with the Creator through the Shades.” Brenda Sullivan, Spirit of the Rocks (Cape Town/Pretoria/Johannesburg, South Africa: Human & Rousseau, 1995), p. 13.
For information on the Celtic cross as ancient navigational instrument and architectural tool, see Crichton E M Miller’s excellent book The Golden Thread of Time (Rugby, Warwickshire, UK: Pendulum Publishing, 2001),