Daniels attended Brown University in Providence, Rhode Island, where he wrote his master's thesis on Frankenstein, and he worked as a musician and as a journalist.

[2] He was the author of five novels featuring the vampire Don Sebastian de Villanueva,[3] a cynical, amoral and misanthropic Spanish nobleman whose predatory appetites pale into insignificance compared with the historical catastrophes which he witnesses in his periodic reincarnations.

A sixth (and presumably final) Don Sebastian novel set in Tibet and entitled White Demon was planned and is advertised by some sources as being available for purchase, but in fact was never completed: Daniels had begun writing it before abandoning it due to the demands of his non-fiction projects and was told when able to resume that his publisher had lost interest.

The Black Castle features appearances by Torquemada and Columbus; in The Silver Skull Sebastian confronts Hernán Cortés; in Citizen Vampire he has a couple of friendly encounters with the Marquis de Sade; and Madame Tussaud makes an appearance in Yellow Fog.

[7] Don Sebastian de Villanueva An unabridged audio-book recording of The Black Castle was released by Crossroad Press in 2018.