So, it's 4716 on Golarion, the Red Revolution began in Galt in 4667, Pomeroy is 124, which means he was born in 4592, which would make him 75 when the revolution started. I figure his parents were probably artists of some sort, and as a young teenager was swept up in the action, but quickly became jaded, and as a way to cope and help out, became a Medium to try to help people keep in touch with their deceased loved ones.
Eventually he realizes he can't help anymore and travels west to take in some renowned chelish artwork and opera in Kintargo to kind of help clear his mind. Alas he couldn't have had worse timing, or better, depending on how you look at it.