Most monarchies are hereditary from parent to child, however the Saudi Throne has passed from the children on Ibn Saud for the last 60 years, which will end with the ascension of Mohammed Bin Salman.
Why did the Saudi Monarchy embrace this method of inheritance? I read that this was a tradition in parts of the Middle East, what was the reasoning behind this?
Thank you historians for taking the time to answer my question.
I can't provide an answer as to why, where or when this practice originated. That being said, this tradition of succession can be observed throughout different historical periods in Arabia.
Al-Walid I bin 'Abd al-Malik (d. 715 CE), was succeeded by his three brothers: Sulayman, Yazīd II and Hisham in that order. This line of succession was interrupted briefly by their cousin 'Umar II^(1).
The monarchy in Kuwait can be used as a modern example. In the nineteenth-century, three brothers ruled successively, Abdullah ibn Sabah and his two brothers Muhammed and Mubarak^(2). Jaber and Salem, sons of the latter also ruled successively.
1: This is briefly mentioned in The Reign of Hisham bin 'Abd al-Malik by Blankinship
2: A somewhat detailed account can be found in The Reign of Mubarak al-Sabah by Alghanim