The Chief of the Naval Staff, (CNS) has been the title of the professional head of the Indian Navy since 1955 and is a statutory position in the Indian Armed Forces held by a four star admiral. As the highest-ranking officer assigned to serve in the Indian Navy, the chief is the principal military advisor on naval affairs and a deputy to the Union Minister of Defence. In a separate capacity, the CNS is a member of the Chiefs of Staff Committee and, thereby, a military advisor to the National Security Council (India), the prime minister and the president. The CNS is typically the highest-ranking officer on active duty of the Indian Navy unless the Chief of the Defence Staff is a naval officer.