The Bornless Ritual, also known as the Preliminary Invocation of the Goetia or simply Preliminary Invocation, originates from the Graeco-Egyptian Papyri Graecae Magicae (PGM), a collection of ancient spells, invocations, and hymns compiled between the 2nd century BCE and the 5th century CE. Initially used for exorcism and healing, the ritual invokes the "Headless One". In modern times this entity has been re-interpreted as the "Bornless One" without beginning or end, who symbolizes the unity of the divine and the practitioner. Some interpretations suggest that the ritual may have connections with the Egyptian god Set. It is also called the "Headless Rite" or the "Invocation of the Bornless One".

Adapted by the Hermetic Order of the Golden Dawn and Aleister Crowley's A∴A∴, the ritual is employed to contact the Holy Guardian Angel, a key concept in Thelema and other esoteric traditions. It serves purposes of spiritual protection, purification, and preparation for deeper magical workings, aiming to facilitate a connection with higher spiritual forces.

Today, the Bornless Ritual remains significant in Western esotericism, especially in the pursuit of the Knowledge and Conversation of the Holy Guardian Angel. Its continued use underscores its foundational role and impact on the spiritual journey in modern occult practices.

The Bornless Ritual is deeply rooted in ancient texts and traditions, drawing from Graeco-Egyptian magical practices. One of the primary sources for the ritual is the Greek Magical Papyri (Papyri Graecae Magicae), a collection of ancient spells, invocations, and hymns compiled between the 2nd century BCE and the 5th century CE. This collection includes various rituals and invocations that have influenced the development of the Bornless Ritual.

The ritual is derived from a specific text within the Greek Magical Papyri known as the "Stele of Jeu the Hieroglyphist in his letter" (PGM V. 96–172). The original ritual was intended as a rite of exorcism. It refers to "Moses" and the "ceremonies of Israel", suggesting a Jewish influence. The Bornless Ritual was first published in England in 1852 by Charles Wycliffe Goodwin as Fragment of a Graeco-Egyptian Work Upon Magic for the Cambridge Antiquarian Society. In 1899, E. A. Wallis Budge included excerpts from it in his book Egyptian Magic.

The adaptation of the Bornless Ritual in the context of Western esotericism owes much to the Hermetic Order of the Golden Dawn (1887–1903). Samuel Liddell MacGregor Mathers, one of the primary founders of the Golden Dawn, is credited with incorporating the ritual into the order's teachings. The Golden Dawn's teachings and ceremonial practices played a significant role in preserving and popularizing the ritual. Israel Regardie's The Golden Dawn provides an in-depth look at the ritual's structure and its significance within the order's framework.

Aleister Crowley's extensive work on the ritual is detailed in his The Temple of Solomon the King, where he emphasizes its use for attaining the Knowledge and Conversation of the Holy Guardian Angel. His "Liber Samekh" offer a detailed interpretation and adaptation of the ritual, which he integrated into his practices. These foundational texts and references form the bedrock upon which contemporary understandings and practices of the Bornless Ritual are built.

The theoretical foundations of the Bornless Ritual are rooted in ancient Egyptian and Greek magical traditions, reflecting a synthesis of Hermetic, Gnostic, and early Christian influences. The ritual calls upon the "Bornless One", a term signifying a primordial, transcendent deity beyond the confines of birth and death. This concept is central to the Hermetic tradition, emphasizing the unity of the divine and the individual soul's capacity to access higher realms of existence. Philosophers such as Iamblichus and the Neoplatonists have significantly contributed to the metaphysical framework that informs the ritual, advocating the practice of theurgy to attain divine illumination.