fall on sword
fall on (one's) sword
To accept the responsibility or blame for a problem or mistake. Likened to the former practice of a soldier using his sword to take his own life for such a misdeed. The CEO fell on his sword when widespread corruption in the company was exposed.
fall on one's sword
1. Lit. to fall down and be penetrated by one's own sword, accidentally or on purpose. He tripped and fell on his sword.
2. Fig. to accept defeat; to go to extremes to indicate one's defeat. (From the ancient practice of a military commander committing suicide this way rather than being captured.) So, because I lost the contract, I am supposed to fall on my sword or something?