Historical clue formulations

• Ottoman Empire founder — 2020-05-28
• Founder of the Ottoman Empire — 2019-12-15
• 13th-century empire founder — 2012-11-03
• Ottoman Turk leader — 2008-06-03
• Turkish Empire founder — 2005-01-09
• Sultan who founded an old empire — 2003-06-13
• Ottoman Empire founder — 2000-05-04
• Ottoman Empire founder — 1999-08-06
• Turkish Empire founder — 1997-12-31
• Ottoman dynasty founder — 1996-11-08
• Ottoman dynasty founder — 1996-01-10