Who said "Patience in adversity is the mark of a true soldier."?

This quote is attributed to Douglas Haig.

Patience in adversity is the mark of a true soldier. - Douglas Haig

"Patience in adversity is the mark of a true soldier."

Douglas Haig Patience

Military Field Marshal British 1861–1928

"I have not the smallest doubt that the credit of this war will eventually rest with the cavalry."

"The general who loses morale loses the battle."

"In any war, the morale of the troops is half the battle."

"Success in war depends upon the moral factor."

"Patience is a virtue I'm still learning."

"I may be a redhead, but I'm not a hothead."

"Patience is a virtue."

"Patience is a virtue I never learned."