Historical clue formulations

• Belgian river in a W.W. I battle — 2023-12-31
• W.W. I battle locale — 2020-12-18
• Belgian river to the North Sea — 2020-08-31
• French/Belgian river — 2020-08-02
• Scene of W.W. I fighting — 2020-06-06
• Belgian river to the North Sea — 2019-04-28
• River in a 1914 battle — 2019-04-07
• Belgian river to the North Sea — 2019-02-12
• Flemish river — 2018-12-22
• River through Flanders — 2018-12-20
• River in W.W. I fighting — 2018-12-12
• River flooded in W.W. I to thwart the Germans — 2018-07-22
• French/Belgian river — 2016-09-22
• Nieuwpoort's river — 2016-08-12
• W.W. I battle site — 2016-07-08
• River to the North Sea — 2016-05-17
• 1914 battle site — 2016-03-27
• North Sea feeder — 2016-02-19
• W.W. I battle site — 2015-11-11
• Belgian river deliberately flooded during W.W. I — 2015-11-06
• Belgian river to the North Sea — 2015-10-04
• 1914 Belgian battle line — 2014-11-08
• W.W. I's Battle of the ___ — 2014-09-23
• River through Flanders — 2014-07-15
• River of W.W. I — 2014-03-28
• River of W.W. I — 2014-03-04
• French/Belgian river — 2013-09-08
• Battle of the ___, 1914 — 2013-07-07
• North Sea feeder — 2013-05-21
• North Sea feeder — 2013-05-15
• Belgian river to the North Sea — 2012-10-07
• River intentionally flooded in W.W. I — 2012-03-03
• River in W.W. I fighting — 2012-02-09
• River of Flanders — 2012-02-01
• River to the North Sea — 2012-01-22
• River through Belgium — 2011-12-21
• River of Flanders — 2011-08-10
• River to the North Sea — 2011-06-26
• River of Flanders — 2011-06-06
• North Sea feeder — 2011-05-05
• Northern French river — 2011-02-08
• River that begins in Nord — 2011-01-27
• River in a 1914 battle — 2011-01-26
• River to the North Sea — 2010-09-09
• River through Flanders — 2010-06-30
• River deliberately flooded in W.W. I — 2010-02-28
• River of Flanders — 2009-05-24
• Scene of W.W. I fighting — 2008-10-04
• Strategic W.W. I river — 2008-06-15
• River of Flanders — 2008-03-19