The Defense Hierarchy Council, also known as the Hierarchy Defense Council, was a military council of the Chiss Ascendancy in the Imperial Era. After a skirmish with Grysk warships, Admiral Ar'alani of the Chiss Expansionary Defense Fleet informed Imperial Navy Grand Admiral Mitth'raw'nuruodo that she had concerns about their current situation, before informing Mitth'raw'nuruodo the Council would be furious if what she were to tell him left the room they were in. After Mitth'raw'nuruodo assured Ar'alani what was said would stay between the two, she told him of potential dangers to Chiss sky-walkers Un'hee and Vah'nya.
The Syndicure of the Chiss Ascendancy was not supposed to have any influence over the operations of the Chiss Defense Force; which were de jure solely the purview of the Defense Hierarchy Council. However, in practice, this separation of branches of government was sometimes broken. The Syndicure could pass laws that regulated the Ascendancy's military, but the Defense Hierarchy Council had ultimate authority over the personnel of the Defense Force, including the Expansionary Defense Fleet. In spite of this, the Aristocra often sought to interfere in Fleet operations. This competition between the Syndicure and the Council often led to members of the Council seeking to "remind" the civilian leaders that the Council had authority over the military.