The conflict - officially known as the Third Battle of Ypres - was fought from July 31, 1917, until the November that year when the relentless rain caused the thick mud for which the occasion is also well remembered.
Among those brave men and women who made the ultimate in that battle was former Spurs and Wales goalkeeper Fred Griffiths.
Born in Presteigne, Fred played locally in junior football before emerging at Blackpool. He made his senior Wales debut against Scotland at Aberdeen in February, 1900, and later that year played against England, making him the first Blackpool player to win an international cap.