The brief synopsis of my review is that if this is remotely based on stories from his Granddad, then his Granddad is the Prince of Liars.Or Sam Mendes made them into lies beyond belief.

There is so much historically wrong with this movie, that it would be quicker to list what was right.

From the fact that 1917 was a year of static warfare until Cambrai; from the fact that in the supposed front line trench in the intro scenes, no-one - literally no-one is keeping a lookout, until we get to the General's dugout; from the fact that never, ever, ever on the western front did troops move into no man's land in a convoy of trucks! from the fact that Colonels in WW1 would never have taken independent offensive action on the Western front; from the fact that nowhere in the British sector of Somme, Picardy or the Calais region would you ever find a white water rapid! The whole film is a tissue of lies wrapped around falsehoods boxed in a laughably comic deceit that a Corporal is going to rush through no man's land in 1917!

Utter nonsense form start to finish. and that's before you get to the non existent character development, the poor acting and the lame script.

Without a doubt the very worst war movie I have ever seen.