21 October 1916
The original plan for the battle was for an attack on boths sides of the River Ancre. Poor weather caused delays, and a new plan was adopted for a limited attack south of the river. The first part of the new offensive was an attack on the Regina Trench, which began on 12.05pm on 21 October and was just about the only success of the battle. The German front line was captured in half an hour, but didn't provide the viewpoint that had been hoped for. The main attack, which was to start on 25 October, was cancelled due to poor weather.
How to cite this article: Rickard, J (28 December 2007), 21 October 1916, https://www.historyofwar.org/firstworldwar/daybyday/1916_10_21.html