While very few people remember him today, the Englishman William Gribbon, who used the pseudonym Talbot Mundy, was one of the most successful and well regarded pulp writers of the 1920s. His stories appeared in many places, including Adventure magazine. It was in the pages of Adventure that Mundy introduced the world to his greatest creation, Tros of Samothrace, a Greek rebel living in the time of Julius Caesar. More than that, he was a swashbuckling adventurer and initiate into a mystery cult, who traveled the Ancient World, fighting against the tyranny of Rome while aiding peoples crushed beneath its iron-shod sandals. Tros is also a peerless sailor and dreams of one day sailing around the world, seeking both excitement and freedom from Roman domination. Consequently, the stories of Tros see him travel the length and breadth of the Mediterranean world, giving Munday the opportunity to show off a wide variety of locations, cultures, and historical events.
In 1934, the publishing house Appleton-Century collected nine Tros novellas together under a single cover and released it. This same collection was re-released in 1958 by Gnome Press and, through this edition, many future fantasy and science fiction writers were first exposed to these well-written stories of historical fantasy. Mundy was a very talented writer, far better than many of his contemporaries, particularly when it came to characterization. His characters have a depth that is usually lacking in pulp fantasy. Likewise, the details of the Ancient World are presented in a way that, while not always historically accurate, nevertheless provide a verisimilitude that nicely grounds them in reality, thereby making some of the stories' more outlandish elements easier to accept. Of course, the adventures of Tros are broadly "realistic" anyway, so it's not much of a stretch. Still, it's hard not to appreciate Mundy's facility with his material; these stories are a lot of fun and good inspiration for players and referees alike.
(Tros of Samothrace is also one of several books that might have inspired the D&D druid class, since Tros makes common cause with the druids in his battle against Rome)