Historical clue formulations

• Holy Roman emperor beginning in 973 — 2022-05-19
• "Red" Holy Roman emperor — 2015-08-02
• Holy Roman emperor known as "the Red" — 2013-07-05
• 10th-century Holy Roman emperor — 2012-07-01
• Holy Roman emperor who succeeded his father in 973 — 2012-01-19
• Holy Roman emperor, 973-83 — 2010-10-30