There is a message when a region joins your realm.
Region Joins Realm (3 days, 19 hours ago)
message to all nobles of Caelum
Dirken Hemmings has changed the allegiance of Junohep to the duchy of the Desert Stronghold, a part of your realm. The region used to be a part of Nothoi.
Together with the lord, the following knights joined your realm: .
During secession, it is listed:
Regions leaving the realm: Chasnoff, Matakonis, Wayburg
Nobles leaving the realm: Johannes, Masil, Johannes, Sethan, Geirr
Not sure what it looks like when a region leaves your realm. Anybody in Nothoi that can tell us what happened when Junohep defected about a week ago?