Historical clue formulations

• Under ___ (brand of athletic wear) — 2021-01-12
• British knight's protector — 2005-08-03
• Hall-of-Fame golfer Tommy ___, called the "Silver Scot" — 2005-03-18
• Meat-packing pioneer — 2005-03-14
• What King Arthur's knights wore — 1999-12-23