| Unknown |
|
| Absolute monarchy |
|
| British overseas territories |
|
| Constitutional monarchy |
|
| Constitutional republic |
|
| Democratic republic |
|
| Diarchy |
|
| Emirate |
|
| Federal monarchy |
|
| Federal republic |
|
| Islamic Republic |
|
| Monarchy |
|
| Republic |
|
| Republic in British |
|
| Socialist republic |
|
| Sultanate |
|
| Unitary presidential republic |
|