West of Sunfall 7
Well, here's what you missed. It started because of his Lost Prophecies. A misnomer—the prophecies were always accessible to those who cared about them, but the Followers proclaimed them "lost" to a City that had censored all Osirian material. And even then the City didn't truly lose them, for when the Speaker ordered me to destroy Osiris's writings, I placed the documents in my private library instead. I don't believe in burning books, regardless of my opinion of the author.
As to why he had to write the prophecies in iambic couplets? Simple: vanity.
List of appearances