Historical clue formulations

• Mid-16th-century year — 2017-01-11
• The year 1551 — 2014-06-10
• Roman 1551 — 2013-04-21
• Mid 16th-century year — 2012-05-20
• Year Boris Godunov was born — 2010-10-03
• Year the National University of Mexico was founded — 2007-05-10
• Year the National University of Mexico was founded — 2005-09-02
• Year of Boris Godunov's birth — 2004-08-22
• Year the oldest college in the Americas was founded, in Mexico City — 2004-03-13
• Livy's 1,551 — 2002-09-09
• 1551, in monuments — 1998-12-22
• Year in Ivan the Terrible's reign — 1996-11-24
• 1551, on monuments — 1995-06-27
• 16th-century date — 1995-06-14