!General Trivia Tropes:
* CreatorsPest: In a [[https://www.reddit.com/r/Fantasy/comments/iekfx9/im_jim_butcher_author_of_the_dresden_files_ama/g2hrixy/?context=3 2020 Reddit AMA]], Butcher said that High Lady Invidia Aquitaine is his least favorite character to write, describing her as a "terrible combination of self-interest and self-righteousness."
* DatedHistory: A relatively minor case; WordOfGod is that the LostRomanLegion that the Alerans are descended from is the [[https://en.wikipedia.org/wiki/Legio_IX_Hispana Legio IX Hispana]], which famously disappeared north of Scotland in 108 AD and was supposedly never heard from again. However, in the years since the series' release, archeological evidence has emerged showing that the IX survived its supposed "annihilation" in Scotland and was camped in Nijmegen in what is now the Netherlands until around the second century AD.
* InspirationForTheWork: As noted below, the series was inspired by combining the ideas of the LostRomanLegion and ''Franchise/{{Pokemon}}''.
* ThrowItIn: An amusing variant - According to Butcher, when he was writing ''Cursor's Fury'', his editor called him and asked for a scene from the book to make a cover for the novel when it would be published in a month. However, Butcher was only on chapter 3 when she called him, and so hastily came up with the scene that would be used on the novel's cover. Butcher then admitted that he found it challenging to figure out how to actually fit that scene into the novel proper when he was writing it.
** Even better, the same aforementioned series of events apparently happened ''again'' when Butcher was writing ''Captain's Fury'' only a year later.
** The elemental spirits that the Alerans can control being named "furies" was based on Butcher watching ''Film/BigTroubleInLittleChina'' while doing research for ''Furies of Calderon'', hearing the word being used in the film, and liking it enough to use it in the series.
* WhatCouldHaveBeen: The working title of ''Furies of Calderon'' was ''Shepherd Boy's Fury'', but Jim Butcher's marketing people made him change it.
* WordOfGod: Many details for the series can only be found [[http://wordof.jim-butcher.com/?s=codex+alera from Jim Butcher himself in an out-of-universe capacity]]. Some particularly noteworthy details include:
** The Vord are all but confirmed to be a space-faring race, and they are actually a biological weapon meant for HostileTerraforming on behalf of a GreaterScopeVillain alien species.
** The gargants are descendants of [[https://twitter.com/longshotauthor/status/13860677665 the megatherium (Giant Ground Sloths)]].
** Butcher has said that if he ever goes back to Codex Alera, it will only be when set a couple of generations after the series proper and the readers can witness how the status quo has been wrecked completely. He has also mentioned that Alera would be utilizing {{Magitek}} SteamPunk by that point - "Furypunk", as he calls it.

!Other Assorted Trivia:
* The series was started by a bet: another aspiring author bet Jim Butcher that he couldn't write a good book based on a bad idea. Jim not only said he could, but allow the author to choose ''two'' bad ideas to base the series on. The other author chose ''Franchise/{{Pokemon}}'' and the Lost 9th Roman legion.
** Jim describes the circumstances in [[https://web.archive.org/web/20200423221253/https://www.youtube.com/watch?v=ylKRYe0ZWHo&feature=youtu.be&t= this video]].
* Butcher has said that in his mind, the series is an "anime cartoon," and he would like the series to be adapted in that format if it ever came to pass.