Pan was an ancient Greek god primarily worshipped in Arcadia who was associated with shepherds and their flocks, and with nature.
He was believed to lurk in caves, mountains, and other lonely, isolated locations.
In some stories, he inflicted his enemies with sudden terror (i.e. panic).
The phrase, "the great God Pan" comes from an ancient Greek folktale recorded in Plutarch's De defectu oraculorum (On the Decline of Oracles), which claims that a Greek sailor near the island of Paxi during the reign of Emperor Tiberius (ruled 14–37 AD) heard a voice cry out, "When you are arrived at Palodes, take care to make it known that the great God Pan is dead."
Early Christian commentaries suggested that this event occurred at the same time as the death of Christ and that the "death" of Pan represented the transition from a pagan to a Christian world.

This story had particular resonance with Victorian literary audiences.
In 1844, Elizabeth Barrett Browning wrote her poem "The Dead Pan", an adaption of Plutarch's story which insisted that proper Christian literature should abandon Greek mythology, with each stanza ending in the words "Pan, Pan is dead."
As a member of the Decadent movement, Machen sought to subvert traditional themes and transgress literary boundaries, an agenda which made Pan a particularly appealing figure.
The title of The Great God Pan appears to have been specifically derived from Browning's later poem "A Musical Instrument" (1862), in which the first line of every stanza ends with the words "the great god Pan".
Machen's use of Pan in the novella may have also been influenced by Robert Louis Stevenson's essay "Pan's Pipes" (1878) and Algernon Charles Swinburne's poem "A Nympholept" (1894), in which Pan is portrayed as the "emblem of the delicious combination of ecstasy and terror."

In a review of the novella for Black Gate, Matthew David Surridge hypothesized that Machen took inspiration from Mary Shelley's Frankenstein (1818) in his portrayal of Dr. Raymond as a mad scientist akin to Victor Frankenstein.
The works of Robert Louis Stevenson, especially his 1886 novella Strange Case of Dr Jekyll and Mr Hyde, were among Machen's most significant influences when writing The Great God Pan.
Critic John Gawsworth also sees Machen's novella as reminiscent of the horror stories of Edgar Allan Poe and Sheridan Le Fanu.
Aaron Worth noted similitude between the death of Helen Vaughan and the theories of alchemist Thomas Vaughan, who is the character's namesake and Helen's disintegration recalls the alchemical concept of the prima materia.
John C. Tibbetts observes similarities between Helen Vaughan and Ayesha, the sexually liberated demonic priestess from H. Rider Haggard's She: A History of Adventure (1886).
Machen wrote that several critics felt that Joris-Karl Huysmans's novels À rebours (1884) and Là-bas (1891) had inspired The Great God Pan, though he did not read either book until after Pan was published.
Upon reading the two novels, Machen concluded that "my critics had not read them either."
Pan was an ancient Greek god primarily worshipped in Arcadia who was associated with shepherds and their flocks, and with nature. He was believed to lurk in caves, mountains, and other lonely, isolated locations. In some stories, he inflicted his enemies with sudden terror (i.e. panic). The phrase, "the great God Pan" comes from an ancient Greek folktale recorded in Plutarch's De defectu oraculorum (On the Decline of Oracles), which claims that a Greek sailor near the island of Paxi during the reign of Emperor Tiberius (ruled 14–37 AD) heard a voice cry out, "When you are arrived at Palodes, take care to make it known that the great God Pan is dead." Early Christian commentaries suggested that this event occurred at the same time as the death of Christ and that the "death" of Pan represented the transition from a pagan to a Christian world.
This story had particular resonance with Victorian literary audiences. In 1844, Elizabeth Barrett Browning wrote her poem "The Dead Pan", an adaption of Plutarch's story which insisted that proper Christian literature should abandon Greek mythology, with each stanza ending in the words "Pan, Pan is dead." As a member of the Decadent movement, Machen sought to subvert traditional themes and transgress literary boundaries, an agenda which made Pan a particularly appealing figure. The title of The Great God Pan appears to have been specifically derived from Browning's later poem "A Musical Instrument" (1862), in which the first line of every stanza ends with the words "the great god Pan". Machen's use of Pan in the novella may have also been influenced by Robert Louis Stevenson's essay "Pan's Pipes" (1878) and Algernon Charles Swinburne's poem "A Nympholept" (1894), in which Pan is portrayed as the "emblem of the delicious combination of ecstasy and terror."
In a review of the novella for Black Gate, Matthew David Surridge hypothesized that Machen took inspiration from Mary Shelley's Frankenstein (1818) in his portrayal of Dr. Raymond as a mad scientist akin to Victor Frankenstein. The works of Robert Louis Stevenson, especially his 1886 novella Strange Case of Dr Jekyll and Mr Hyde, were among Machen's most significant influences when writing The Great God Pan. Critic John Gawsworth also sees Machen's novella as reminiscent of the horror stories of Edgar Allan Poe and Sheridan Le Fanu. Aaron Worth noted similitude between the death of Helen Vaughan and the theories of alchemist Thomas Vaughan, who is the character's namesake and Helen's disintegration recalls the alchemical concept of the prima materia. John C. Tibbetts observes similarities between Helen Vaughan and Ayesha, the sexually liberated demonic priestess from H. Rider Haggard's She: A History of Adventure (1886). Machen wrote that several critics felt that Joris-Karl Huysmans's novels À rebours (1884) and Là-bas (1891) had inspired The Great God Pan, though he did not read either book until after Pan was published. Upon reading the two novels, Machen concluded that "my critics had not read them either."
The Great God Pan