From the back cover:

“When Esau Cairn was sent across space to the demon-haunted planet of Almuric, he knew nothing of his destination. The secret discovery of the scientist who had invented the space-transition machine, Almuric was a world of strange and terrible beings, of savages and swordsmen, or winged monsters and incredible secrets.

"How Esau, alone on Almuric, with nothing but his wits and his muscles to protect him, faced Almuric’s worst perils to make himself master and monarch is a novel of “heroic fantasy” worthy of the creator of the Conan stories."

Lastly and least, “interplanetary” novels are correctly typed as heroic fantasy, as plausibility in access to or in the nature of, the alien world are very low priorities for the author of such a tale.

In most characters in which Howard spends the kind of emotional investment that we see with Esau Cairn, there is an attempt at a catchy name. Not here. I take this as an indication that the morality of the character trumped the marketability.

To look for a character that had a deep moral grounding and a catchy expression in the name, Solomon Kane jumps right off the shelf. The reader oh the Kane stories does discover, toward the end of the cycle, that Kane’s juju staff is in fact the scepter of King Solomon. Howard used the Old Testament of the Bible as source material quite often, in particular rewriting the story of Jacob wrestling with the Angel of God, as one in which the angel is a woman, an emasculating force, that challenges Bran Mak Morn while he is in disguise and unmasks him as a true king.

We now read closer to the genesis of Esua Cairn, drawn from the two pillars of Howard’s heritage, one his genetic, the other his didactic source.

First, his patrimony, being Celtic, is represented in the Celtic [Gaelic] term cairn, for monument.

Second, his cultural influence as a Bible Belt American of the early 20th century was undeniably Christian and Old Testament as expressed in the name Esau, which means “Hairy.” [In his first letter we find that Howard has promoted a lecture on Ben Hur by a local reverend.] Esau was the brother of Jacob, who was voluntarily disinherited in favor of Jacob, whose name has been translated as “tricky wrestler.” I have the sense that Howard’s choice as Esau for the first name had as much to do with the fact that Esau was “hyper-masculine” as that he did not inherit the patriarchal position at the head of the tribe.

I this light Esau Cairn, the character, is Howard’s monument to the masculine dispossessed, the man with the stuff of heroes flowing through his veins, that cannot or will not submit to the emasculating precepts of civilized life and who would rather die where he stood, facing off against the enforcers of unjust laws, rather than seek privilege at the price of submission.

Esau Cairn clearly embodies Man the species/gender when cast down naked on an alien planet. Esau Cairn is the most fundamentally anti-Islamic, ant-Puritan character in fiction. In this reviewers assessment he represents the deep cultural yearnings of his creator for a dystopia of magnificent proportions, for only in such a world of predatory peril could Man, as he was originally cast down by God, be able to fulfill his natural purpose.