As I grew up reading speculative fiction, all of my reading was based on the paperbacks I could pick up at the local bookstore and, eventually, a few hardbacks I could get as I grew older and could afford them. I didn't have the experience that so many older readers had, of reading speculative fiction from pulp magazines—and yet, in popular culture (or perhaps "popular imagination" would be more appropriate), those pulps are the primary format for getting to science fiction. It would appear that those early artists did their job too well—in an effort to capture the consumer's attention and imagination with bug-eyed monsters and young women with ripped bodices, they stigmatized the entire genre for generations. Fortunately, I know that those pulps produced a lot of great writing—Asimov and Heinlein got their starts from them after all. And in the past couple of years, I've made something of an effort to read even earlier pulp fiction, finding that there was some really interesting story-telling going on, further proving to me that, while those covers and the popular imagination were fun, they aren't accurate at all.
And then I read stories like The High Crusade, which, while not containing bug-eyed aliens and half-naked women, does show that some of the stereotypes were based on fact. The High Crusade is not a terribly well-written story, but it is a great example of the free-thinking imaginative plots that seem to typify the stereotype; in this case, the story asks what would happen if aliens had visited a medieval English village. The obvious answer—the English get squashed—doesn't make for a particularly good story, nor do its natural consequences align themselves with history as we know it: with a foothold in England, an aggressive alien race capable of space flight should be able to take over a medieval world.
Poul Anderson uses a nifty plot device to frame his story—humans in the far future have uncovered an unexpected human outpost and are using a historical record to figure out how humans achieved space flight and gained control over a section of galactic space far earlier than anyone knew. The document is a record kept by one Brother Parvus describing the English reaction to the attempted invasion and what follows. In a scene that is repeated often throughout the novel, the alien Wersgorix have completely forgotten such things as hand-to-hand combat and diplomacy since they have advanced so far beyond them, and when their ship lands outside the village of Ansby, they are rudely received and routed save one man by the hand-to-hand capable English. The local lord, Sir Roger hits upon the idea to use this new weapon to defeat the vile French and then to free the Holy Land in what surely will be the shortest of crusades. But he and his entire village (which he puts on the ship to carry with them as he moves further afield) are tricked by the remaining alien, Branithar, and are catapulted into the reaches of galactic space to another Wersgorix colony, where Branithar expects the near-barbarian English to be routed.
The framing device fails a little, however, since its existence offers some indication of how the story is going to turn out. And so it goes: using medieval tactics, Sir Roger and his men set about to overthrow the Wersgorix empire, in part to protect Earth from them. After a few battles, Sir Roger makes allies out of the enemies of the Wersgorix, allies who also believe the English have more skill and power than they really do, and yet there seems little that can stop the English.
The only real challenge to Sir Roger comes from his wife, an unhappy Lady Catherine, and one of his own soldiers, Sir Owain, who plot to overthrow Roger and return the ship and its weapons to Earth. Their unhappiness stems from Roger's apparent unwillingness to go home; neither of them accept Roger's assertion that now that the Wersgorix know of Earth and its people, they will be determined to return there and eradicate human competition. Catherine plays the medieval scorned woman very well, never realizing that her pushing Roger away is more likely to cause him to want to stay out among the stars than to return home to a shrewish wife. And Owain assumes too much, thinking Catherine's working with him a sign that she loves him more than her husband; despite his appearance and actions, it becomes more and more clear that Owain is not very chivalrous at all.
Anderson is careful to use some details as impediments to human security. Potential allies don't trust the humans, who have to make do with a scanty but growing knowledge of the technology they command. But with the eternal optimism of Golden Age speculative fiction, humans always find a way to win through—even at one point casually tossing atomic weapons they have stolen from a catapult and amazing themselves at the destructive power they unleash. Such scenes are, I think, unintentionally funny, especially with 50 years of perspective and cynicism. But the human interaction is fairly timeless, not out of place in current heroic fantasy, and it is a telling point that humans' own inability to communicate adequately threatens the very existence of their home world. Such a dark prospect is never explicitly stated, but it is a consequence of the mutiny that Catherine and Owain prepare and an interesting scrying into the darker future of speculative fiction.
The High Crusade is a quick, somewhat frivolous read. It is difficult to take the plot turns seriously, but then, it's not necessary to do so in order to enjoy the book. The novel stands as a solid example of the more common speculative fiction stories, the ones that have given speculative fiction the reputation it cannot shake. And even then, The High Crusade shows thoughtfulness and care in its construction and gives the reader some fun along the way. If The High Crusade were a movie, I'd recommend renting it or maybe seeing it as a matinee. As a novel, I think it would be delightful fodder for plane travel or a day on the beach.