The original letters patent which created the title determine the order of succession.

There are also other sorts of order of succession than hereditary succession (such as line of non-hereditary succession to democratic state offices).

Hereditary monarchies have used a variety of methods and algorithms to calculate the order of succession among possible candidates related by blood or marriage.

In hereditary monarchies, particularly in more ancient times, seniority was a much-used principle of order of succession.

This has led sometimes to an order of succession that balances branches of a dynasty by rotation.