In the Majestic Wilderlands and various post I mention the Imperial Prince and occasionally a King of Ghinor. An explanation of the difference between the two may prove useful for developing your milieu.
A short historical sequence of Ghinorian History goes like this
The Successor Realms
After the exodus the Ghinorians were divided into seven tribes. Six were given different portions of the Valley of Ghinor to live in. The seventh, the Tribe of Loris, was devoted to the worship of Mitra. They were scattered among the other six but lived apart while leading the worship of Mitra.
After away the tribes began to fight one another. Territory, women, resources, the usual things caused arguments to occur. Occasionally a Judge will be anointed by the Tribe of Loris when a external threat or serious dispute arises. Eventually this system proved incapable of handling the Vahon a barbarian tribe that migrated into the region. The Tribe of Loris anointed seven warriors who trained seven more each to form the first paladins.
To join the paladins one cast all ties to a particular tribe and fought for Ghinor and Mitra. Their adoption of Chariots gave them exceptional mobility and checked the threat of the Vahon. Judges were still appointed but they became more legal advisors to settle disputes between the tribes.
Even this system started to creak when the Princes of the Tribes became wealthy and powerful. Many became little better than tyrants and reduced their fellow Ghinorian into mere subjects. When the people cried for deliverance and asked for a King to check the power of the Princes. The tribe of Loris reluctantly agreed and anointed Valol, the then current leader of the Paladins, as the first King of Ghinor.
The Kings had their own land and their own sources of income. They did not rule the individual tribes directly but rather acted through the six princes and the patriarch of Loris. They could and did punish princes that abused their power and attacked other tribes. Eventually the power of the Kings grew at the expense of the Princes and the last Kings were little better than tyrants themselves. Civil wars regularly broke out on the anointing of a new King
After 800 years the Kingdom of Ghinor fell when a new wave of Vahon barbarians entered the region and conquered much of the valley of Ghinor.
It took two hundred years for the Ghinorian win their freedom again. They were lead by the Prince of Shalol the last free tribe. When the Valley of Ghinor was liberated and the Vahons were finally conquered the Ghinorian Empire was proclaimed. The Prince of Shalol refused to restore the monarchy. Instead they had themselves crowned seven times, one for each of the tribes of Ghinor. They styled themselves as the Imperial Prince of the Seven Tribes of Ghinor.
To manage the Church of Mitra they appointed a pontiff of the Tribe of Loris. A pontiff being an assistant to the old office of the Patriarch. As the centuries wore on the tribal lines blurred. The Tribe of Loris was transformed into the Church of Mitra and accepted any Ghinorian into Mitra's service. When the Empire fell and along with the office of the Imperial Prince the colonies of Ghinor proclaimed themselves Principalities and their rulers as Princes not Kings.
Because the office of the patriarch was lost along with the other six titles of the Imperial Prince, the Church of Mitra became separated from the Principalities. In the Karian Islands and for a time when the Restored Empire existed the office of Imperial Prince was restored along with the patriarchy.
The distinction between the King and the Imperial Prince was inspired by Rome's history with their Kings and Emperors. Augustus carefully preserved the forms of Republican Rome while retaining all the real power. His titles were carefully chosen to give the impression that he was restoring the old values of Republican Rome. He did not want to wind up as Julius Caesar did.
The same for the early Imperial Princes. They crafted the political structure of the early empire so that it preserved the forms of what the Ghinorian people considered ideal. The early days of the tribes settlement of the Valley of Ghinor. But the reality was that the Imperial Prince held all the power.
I know some of you are interested in the Majestic Wilderlands and for the rest I hope this is useful in developing your own political and religious backgrounds for your milieus.