"The Shadow Kingdom" is a fantasy novelette by American writer Robert E. Howard, the first of his Kull stories, set in his fictional Thurian Age.

Despite the fact that the Picts are ancient enemies of the Atlanteans, Ka-nu confides in Kull and tells him to expect the arrival of Brule the Spear-Slayer around sunset.

Brule explains that Kull's life is in danger and shows him a series of secret passages which riddle the palace.

Brule reveals that the Serpent Men, an ancient pre-human race who had founded Valusia but were almost extinct, rule from the shadows, using their Snake Cult religion and ability to disguise themselves with magic.

He and Brule are, through an illusion, tricked into a separate room instead of the real council, surrounded by Serpent Men disguised as the councillors.

Early in the story, before the Serpent Men appear, Kull's thoughts on the matter are described: Strange to him were the intrigues of court and palace, army and people.

This is touched on again shortly afterwards when, on seeing a Serpent Man masquerading as himself, Kull is momentarily confused: He stepped back, his mind reeling.

[1] "The Shadow Kingdom" was later voted the most popular story of the August 1929 issue in a poll of Weird Tales readers.