Historical clue formulations

• Prince of Monaco beginning in 2005 — 2026-08-15
• Physicist Einstein — 2023-09-11
• Real name of George VI — 2021-04-23
• Queen Victoria's husband — 2016-08-02
• With 39-Down, speaker of this puzzle's quote — 2013-12-11
• Name on a London hall — 2013-03-23
• See 18-Across — 2013-03-14
• Physicist Einstein — 2008-08-25
• King of Belgium — 2007-07-28
• *Title fellow in a 1971 #1 McCartney hit — 2006-10-18
• Prince ___ (frock coat) — 2006-07-15
• King of Belgium beginning 1993 — 2005-07-23
• Victoria's prince — 2005-03-16
• Queen Victoria's prince — 2004-04-12
• Consort to Queen Victoria — 2003-12-28
• "Fat" Cosby character — 1996-09-03
• London's Royal ____ Hall — 1995-09-25
• Queen Victoria's husband — 1994-06-28