I have been studying Ottoman history for more than a year now (particularly 16th Century). I constantly come across the tradition of fratricide. According to a book I bought at a Museum in Istanbul, some sixty princes were strangled to death by their brother in the years leading to the collapse of the Ottoman Caliphate, after Mehmed II (The Conquerer) supposedly made it permissible in the Law of the land.
The rationale being that it was better for a sultan to kill his brothers than to risk the stability of the empire which may arise from power struggle.
With all the Mufti's at their disposal, and with the height of Islamic knowledge the Ottoman's were surrounded with, I am eager to understand if whether or not killing a sibling prince is even remotely permissible or justifiable, even pre-emptively, to secure the future of a Caliphate?
"However, the famous article from Sultan Mehmed II the Conqueror's Law of Governance states that "Any of my sons ascend the throne, it acceptable for him to kill his brothers for the common benefit of the people (nizam-i alem). The majority of the ulama (muslim scholars) have approved this; let action be taken accordingly." -- Daily Sabah (amongst others)