Trojan Horse: The First Crusade

Caballo de Troya (Spanish for Trojan Horse) is a novel (the first of a series of eight) written in 1984 by Spanish journalist and ufologist J.J. Benítez, which became famous in Spanish-speaking countries and in Brazil, so far without an English translation.
It deals with a supposed successful attempt by US military in 1973 to send time travellers back to Israel during the time of Jesus Christ, to witness his days of ministry by the year 30, and to a certain degree even interact with him and other people.
Benitez, born September 7, 1946, in Pamplona, Navarre, northern Spain, got a journalism degree in 1965 and joined newspaper La Verdad of Murcia in January 1966. Over the next few years, he became interested in the UFO phenomenon, then sweeping headlines and bookshelves all along the western world, and he eventually left journalism in the late 1970s. He wrote in his website that he first became interested in the "real" life of Jesus around that time, when a team of researchers said that the Shroud of Turin showed traces of Jesus' body. These claims have later come under scrutiny, but the fact has not stopped the flow of new Caballo de Troya's books.
The author has claimed the time-travel part of Caballo de Troya is fiction, but that it contains "more truth than people think" suggesting, given he purports to be "a UFO researcher", that he might be claiming alien contact. If Benítez had no further ambitions other than to remain confined within the realm of pure fiction, perhaps they would stand alone by whatever literary or imaginative merits they might have. But the author insists that most, if not all, events in his novels are real.

The book is narrated as if it is a true report of how the author was approached by an unnamed retired US Air Force pilot, referred to as "The Major" in the book, who in an elaborated indirect way tells the author how to find classified documents telling the story of the Trojan Horse Operation, in which The Major took part as a time traveller sent to witness the last weeks of Jesus' life through a time-travelling device sent back in time by the US military in an Israel base in 1973.
A lengthy, detailed "technical" description of the time travel process ("inversion of quantum swivels") is provided. The time-traveller and the time-travelling vehicle are said to have been wrapped by an artificial skin to avoid biological contamination. The Major, who becomes the narrator of the story, is called "Jason" during the mission, and learns some Aramaic and Greek.
It is "revealed" that many of the amazing stories of eclipses, earthquakes after Jesus' death and his transfiguration were linked to extraterrestrial influences. Jesus' physical appearance is described as almost Nordic, with hazel eyes and very tall (he is sometimes called "The Giant", physically and metaphorically in the book).
Unlike the sequels the first Caballo de Troya is an intriguing fiction story, written with some style and containing attractive plot twists. Even as the 1970s UFO mania has lost traction in Spanish-speaking countries, Benitez has retained solid sales and certain celebrity on the basis of his book series.
The following 7 sequels expand on the issued and reveal more detail. Caballo de Troya 8, Jordán was published in Spain recently.