If you want Hollywood stealing lines look no further than Cromwell and Richard Harris.(He will always be Dumbledore for me)
In Cromwell at the battle of Edgehill the warty faced dog-robber looks piously up to Heaven and whispers "Oh Lord, thou knowest how busy I shall be this, if I forget thee, do not thou forget me." And then launches off like a mad thing to have at it with the brave Royalist forces.
Problem. Cromwell wasn't at Edgehill. He was 20 odd miles away.
The prayer should have been said by Sir Jacob Astley - who was at both Edgehill the first major battle of the war and at Stowe on the Wold - the last major battle. Oh and he was a Royalist.