The Royal Hunt of the Sun, while grounded in historical events, transcends the boundaries of a simple history play. Drawing from William H. Prescott’s History of the Conquest of Peru (1886), Peter Shaffer infuses the narrative with symbolic alterations to amplify its thematic resonance. For instance, Shaffer portrays Atahuallpa as the same age as Jesus at the time of the Crucifixion, imbuing the character with a Christ-like symbolism. Similarly, he condenses the lifespan of Francisco Pizarro, who historically was murdered at the age of seventy in 1541, to serve the play's dramatic purposes.

Critics have been divided over Shaffer's ambitious work. Some hailed it as a masterpiece, while others dismissed it as a "showy fraud." Notably, Robert Brustein critiqued the play as pretentious and accused it of "sentimental sermonizing." Despite such criticism, the play’s visual splendor and theatrical vitality were widely acknowledged. As with Equus, The Royal Hunt of the Sun faced skepticism, yet it gained admiration for its bold execution.

Shaffer’s approach to grand themes inevitably invites scrutiny. He himself described the play as exploring "a man’s search for immortality," a theme of profound depth. Acknowledging the play’s intent to conjure spectacle and magic, Shaffer aimed to create an "entirely and only theatrical" experience, challenging the notion that such enchantment could no longer captivate contemporary audiences.

The play possesses an epic scope, showcasing the historical and chronological fluidity that Shaffer would further develop in works like Amadeus. It previews the thematic and abstract conflicts found in Equus and delves into personal struggles explored in Shrivings, Equus, and Amadeus. The obsession with fame and reputation that torments the narrator in Amadeus finds its roots in The Royal Hunt of the Sun. Dennis Klein eloquently defends its grandiose themes and heroic characters, emphasizing that the play was crafted for the stage's dynamic canvas, not the static page. While the language may appear overblown at times, it remains consistently poetic, which justified its inclusion in Stanley Richards’ anthology Best Plays of the Sixties in 1970.