Continuing on through the collected works of Xenophon, we next have Hellenica, which much like Herodotus's Histories is intended as a historical narrative. This time, it picks up the account in 411 BCE, and covers about fifty years, to 362 BCE, which is apparently the year of the Battle of Mantineia. Apparently, it picks up the narrative thread of the Peloponnesian War immediately where Thucydides' history abruptly ends (which is also on my reading list, and I only know this because the information was conveniently included in the front of my translation of Hellenica), and may have been written just for his friends as a sort of historical "vanity" publication. Like The Ten Thousand, this is covering a topic to which Xenophon was a contemporary, so it is considered an important primary source, and hopefully has a bit more historical veracity than his not-really biographical treatment of King Cyrus, who founded the Persian Empire.
Literally, the title of this piece translates to "the education of Cyrus," though in truth only about the first book or two cover Cyrus's "education," while the others describe the rest of his life. This is meant as a sort of "how to" book on how to rule well, in the form of a biographical treatment of Cyrus, but unlike in The Ten Thousand, Xenophon is not here describing contemporary events, and many historians doubt that this is in more than the most general of ways an accurate depiction of Cyrus's life. Note: by "how to," I mean a book on how to rule as a semi-benevolent authoritarian dictator who is loved and feared by his subjects.
I don't actually know how much this post will help you in ridding your works of pesky anachronisms, but the title just seemed to clever to resist. If you're not already familiar, an anachronism is a literary, spatial or temporal (usually temporal) transplant. A detail, a phrase, an expression, a device, or really anything else could be an anachronism; most commonly these are stock expressions or devices of our own time that we accidentally put into our works. Nor are they unique to literature, as there are plenty of examples in movies and other media. For instance, perhaps a period movie might show cars from a later model year driving around in the background. Or my personal favorite, when an author or screenwriter has archers "fire" their arrows, an expression which could not predate the advent of firearms. This last one even made its way into The Lord of the Rings movies (notably during the battle at Helm's Deep).