In Istanbul, changes in the nature of dynastic politics led to the abandonment of the Ottoman tradition of royal fratricide, and to a governmental system that relied much less upon the personal authority of the sultan. The changing nature of sultanic authority led to several political upheavals during the 17th century, as rulers and political factions struggled for control over the imperial government. In 1622 Sultan Osman II was overthrown in a Janissary uprising. His subsequent regicide was sanctioned by the empire's chief judicial official, demonstrating a reduced importance of the sultan in Ottoman politics. Nevertheless, the primacy of the Ottoman dynasty as a whole was never brought into question.