The High Crusade is a science fiction novel by American writer Poul Anderson, about the consequences of an extraterrestrial scoutship landing in Medieval England.

[3] Anderson's work was nominated for a Hugo Award in 1961,[4] and was adapted into a 1983 wargame The High Crusade of the same name by TSR, Inc. and into a motion picture of the same name in 1994.

[6] It is 1345, and in the English town of Ansby (in northeastern Lincolnshire), Sir Roger, Baron de Tourneville, is recruiting a military force to assist king Edward III in the Hundred Years' War against France.

However, the aliens, having forgotten hand-to-hand combat since it was made obsolete by their advanced technology, are caught off-guard by the angered Englishmen, who mistake the craft for a French trick.

Sir Roger formulates a plan that with the captured ship, he can take the entire village to France to win the war, and then liberate the Holy Land.

The Crusader arrives at Tharixan in days, and Sir Roger learns of this new world: it is sparsely-populated, with only three fortresses, Ganturath, Stularax, and Darova (the chief base).

Sir Roger, in order to intimidate the aliens, makes up tall tales about his estate, "which only took up three planets" and his other accomplishments, including a very successful conquest of Constantinople.

With Lady Catherine, Sir Roger's wife, Montbelle corners the baron and demands that he help the people of Ansby get back to Earth.

A millennium after the main events of The High Crusade, the holy galactic empire founded by Sir Roger and his people finally reunites with long lost Earth.

Rating it five stars out of five, Galaxy reviewer Floyd C. Gale noted that the novel's "characters are well-drawn" and declared it "definitely a can't-be-put-down enthraller.