Keep in mind that it is possible, and legal, for a realm to give up or surrender in a war, resulting in the loser being absorbed into the winner, especialy if the losing realm has been reduced to something that could not survive on its own.
Minus the war, that's what politically was forced upon Solaria. The 'war' was Sun Hall switching, leaving BR and Tranquil, then Tranquil left. A single non-productive non-capital stronghold would not have supported itself for more than a minute.
