The First Battle of Passchendael, October 12, 1917.

Aftermath, morning of October 13, 2017.

The ground phase of the First Battle of Passchendaele commenced, and largely took place, on this day in 1917 after a period of artillery preparation over the prior days.  Artillery was in part in effective as the ground was waterlogged due to intense prior rain storms.

The battle was principally an Australian and New Zealand one from the Allied side, with some support by the British and the French.  The attack had limited objectives and achieved limited success as well. Today it tends to be remembered as a costly battle for New Zealand in particular and for its horrible weather conditions.

In that sense, it's come to symbolize the horrible conditions of the Great War.

New Zealand signaler.