The triple knot can be dated as far back as the Iron Age but became frequent by the 4th-century BC. Trinity Knots may draw on the Celtic significance of Earth, Sea, and Sky or Life, Death, and Rebirth. Or it can symbolize the Celtic Triple Goddess: The Mother, the Maiden, and the Crone. The symbol was then adopted by the Christian Monks in the 7th century in many insular texts to represent The Father, The Son, and The Holy Spirit.