Historical clue formulations

• Exploratory trip — 2025-07-04
• Initial tentative attempt — 2024-08-17
• First attempt — 2020-11-15
• Sudden attack — 2020-04-21
• Inroad — 2016-09-30
• Sally — 2015-06-05
• Incursion — 2014-11-09
• Raid — 2014-09-17
• Venture — 2013-01-12
• Raid — 2012-01-30
• Venture — 2008-02-10
• Initial venture — 2007-06-29
• Sudden strike — 2006-04-14
• Initial venture — 2003-07-01
• Incursion — 1999-02-02
• Quick raid — 1998-02-16
• Brief incursion — 1995-03-12