A kingdom is a state ruled by a monarch, in the literal meaning of the word. This was also an old form of hereditary autocratic government, in which the ruler was supported by an aristocracy appointed by the king or queens. The concept of succession was based on a direct lineage of family heirs. In practice, the hereditary succession process created more wars and grabs for power between siblings.
Examples of Kingdom:
|England- Hereditary monarchy|
France- Kingdom/empire founded by Charlemagne, succession interrupted by French Revolution, Napoleon. Followed by restoration of the Bourbons and final abolition of monarchy by the Second Republic in 1848.