I have a scenario in which the Kingdom of Aderia has King X of House Harranshield. A civil war to push the claim bannerman Y (of House Bloodshield) has on the throne (because his mother was the daughter of the former king) has been declared and a decade of bloodshed ensues. This decade of bloodshed ends when peace is signed and King X agrees to share the kingship with Y jointly and equally, and the two spend the rest of their reign consolidating the realm and repairing the damage the war caused.

Both X and Y's eldest son, still of different houses, now have an equally valid claim to the throne. When their father's died, rather than risk another civil war, they continued to share the Kingship. A law was put forward for royal approval by the small council advisors of both kings that required two kings in power at all times.

How might Aderia survive? It needs effective leadership to survive, but at the same time, I see issues rising;

Conflicts of Interest
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Okay, so King X wants to do something with law W because it would benefit him. King Y says no. Who gets his way?

Politics
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King X makes an alliance with neighboring Meralia and seals it by wedding his daughter to the heir of that country. However, King Y refuses to acknowledge that alliance because it puts King X's grandkids on the throne of Meralia in a couple generations.

### Trade?

King Y makes a trade deal with that neighboring merchant republic Aestoso. This deal harms King X's interests, however, and he refuses to abide by the conditions.

These are merely just some of the many possible problems that could arise. Now, I know you would say something like; "make a parliament". All this works fine in a country with relatively low crown authority, but I need Aderia to have unusually high crown authority.

So, keeping in mind political problems, can Aderia function with two equally-powerful kings?

**Inheritance**

The throne only passes on when both of the joint kings have died.