The senior tempter in C.S. Lewis’s The Screwtape Letters is Screwtape.
Screwtape is the experienced demon who writes letters advising his junior nephew, Wormwood. Lewis’s satirical novel was first published in book form in 1942, after appearing in serialized form in the Anglican newspaper The Guardian. The letters reverse the usual perspective: a senior devil explains how to tempt a human patient, while the reader infers the moral and spiritual lessons.
The book’s humor comes from treating destructive habits as professional techniques within a demonic bureaucracy. Screwtape’s advice concerns distraction, vanity, social pressure, and distorted thinking rather than spectacular supernatural events. Wormwood is the junior tempter, not the senior figure. The Screwtape Letters is an epistolary work, meaning it is constructed from letters, and it remains one of Lewis’s best-known works of Christian apologetic satire.