Complex sentence: Humayun served as the Vice Chief of Naval Staff until 23 June 2010 and retired from the Navy after competing his term when he was succeeded by Vice Admiral Asif Sandila in 2010.
Split into simpler sentences: Humayun served as the Vice Chief of Naval Staff until 23 June 2010 and retired from the Navy after competing his term. He was succeeded by Vice Admiral Asif Sandila in 2010.