So this was love! I had escaped it for all the years I had roamed the five continents and their encircling seas; in spite of beautiful women and urging opportunity; in spite of a half- desire for love and a constant search for my ideal, it had remained for me to fall furiously and hopelessly in love with a creature from another world..."
Ask anyone about Edgar Rice Burroughs, and one word will come to mind: Tarzan. Among all his works, Tarzan alone has become an integral part of our popular culture, to the point that any civilized-feral culture shock story will draw comparisons to the seminal character. However, in terms of literary influence, another one of Burroughs's works may be even more important. His John Carter of Mars (or Barsoom, in the Martian native tongue) series serves as one of the earliest examples of a space opera*, featuring a faraway planet, strange creatures, a passionate romance, and, of course, martial combat.
The first novel in the series, A Princess of Mars, first introduces us to John Carter, a confederate soldier who is inexplicably transported to Mars. Once there, he finds out that the society is nearly barren of resources, and as such, has reverted in large part from an advanced, intelligent society to a number of barbaric, warring tribes. John jumps from tribe to tribe, learning their customs and befriending their natives, before finally setting off on a mission to save the entire planet from destruction. On the way, he meets the titular Princess (who unlike the four-armed insectoid Green Martians, is completely humanoid), and falls head over heels (as you can see in the quote above). One of the book's weak points is its poor handling of female characters (something that, unfortunately, carried through to a lot of the science fiction genre). The Princess, Dejah Thoris, has little to no agency, and serves only as a damsel-in-distress, and, to a lesser extent, a source of exposition and explanation for John. The other main female character, a Green Martian, at least has a story and motivations, but is also placed in the story to spur a male character to action (in this case, Tars Tarkas, a Green Martian that John befriends).
APoM was released nearly a century ago, in 1912. The age of the book alone is dizzying, as many of the aspects of the story are considered genre tropes, though these are admittedly borrowed from older genres such as romances and westerns. The fact that "Princess" is getting a big budget film adaptation soon is ample evidence of this; it's unlikely that they'll even have to change a great deal of the plot. The only places that the book truly shows its age is in some of the antiquated phrasing, and the aforementioned outdated thinking (at one point, Carter comments that the princess's naiveté is "good, feminine logic").
That said, the book has some technical issues that even age doesn't completely justify. This is understandable. A Princess of Mars was Burroughs' first full novel (though the first Tarzan novel was published at the same time, I believe what would eventually become A Princess of Mars was written first), and some of the amateur mistakes shine through. The most glaring problem, in my opinion, is Burroughs's ham-fisted use of foreshadowing -- but foreshadowing is the wrong word. Fore-outright-telling-you-what-is-going-to-happen is the closest I can come to describing the issue. At one point, John Carter meets a ferocious Martian "dog" who attacks him, and comments, before even resolving the attack, that the dog would one day become his close companion and risk his live to save Carter. This occurs often in the early stages of the novel, when the characters are being introduced, and it gets old quickly.
The first Barsoom novel is probably not one that is going to keep a modern reader on the edge of his or her seat from cover to cover. It lags in places, and many events tend to be quite similar. For example, Carter first arrives at a tribe of barbarians and is forced to adapt and fight his way into their good graces. Later, he falls in with another tribe, and goes through the exact same process with a slightly different outcome. These issues are worth the read for Science Fiction literature fans, however, to experience such a significant piece of the genre's history. At the very least, the next time you watch a science-fiction show or film you'll be able to roll your eyes and say "ERB did that 100 years ago."
Download A Princess of Mars for free at Project Gutenberg
*Technically, according to the experts at Wikipedia, the Barsoom novels are classified as "Planetary Romance," not "Space Opera." The distinction is mostly academic -- the Barsoom novels certainly inspired later space operas, such like Star Wars.