Historical clue formulations

• Chief — 2016-09-18
• Bigwig — 2016-03-23
• Bigwig — 2011-07-21
• Big gun — 2010-10-24
• Top dog — 2010-06-14
• Chief — 2008-03-12
• Boss — 1999-05-11
• Big chief — 1998-09-09
• El jefe — 1997-01-26