In ancient civilizations, the removal of the human penis was sometimes used to demonstrate superiority or dominance over an enemy. Armies were sometimes.
Penectomy is penis removal through surgery, generally for medical or personal reasons. Cancer, for example, sometimes necessitates removal of part or all of the penis. The amount of penis removed depends on the severity of the cancer.
For them, removing the entire penis and testicles can be a remarkably fulfilling, relieving experience, even though they may still identify as male.