Final answer:
The major cause for the shift in war poetry from the chivalric to the realistic was the insight gained from close contact with the battle.
Step-by-step explanation:
True. According to the lecture, the major cause for the shift in war poetry from the chivalric to the realistic was the insight gained from close contact with the battle. The poets Wilfred Owen, Siegfried Sassoon, Rupert Brooke, and William Butler Yeats published work that put the inhumanity and suffering of the war on full display, conveying the horrors of the battlefield. This shift in perspective allowed for a more honest portrayal of war, moving away from the romanticized and idealized notions of combat seen in earlier poetry.