Sir Edmund of Yorke is a renowned theologist and investigative journalist that deals with cults and other paranormal activities.
His body of work spans a wide variety of cult activity, and is some of the most important pieces of written text in the mythos of Raven.
Through unexplained means he has achieved unnatural longevity - possible due to his exposure to these cults - as his texts appear during wildly different times.
Background
Sir Edmund of Yorke, as he is currently known, only came into public knowledge thanks to his extensive reporting on The Ravens during the first plague, documenting the order's immense dedication to helping the sick.
As he was so devoted to his work, he rarely had time to write down his memoirs, but it seems he might have plenty of time to gather his thoughts and put them into paper, though how much paper he'll need, only he knows.