The Fatal Mistakes of Vito Corleone: When the Godfather Faltered

Even the most powerful criminal masterminds can fall victim to their own hubris. Vito Corleone, the revered Don who built an indestructible family empire through decades of strategic brilliance, made a series of catastrophic missteps in his twilight years.
Blinded by pride and loyalty to an outdated code, the once-unflappable Vito began making disastrous judgment calls that rapidly unraveled the very legacy he had sacrificed everything to construct. From egregious succession planning failures to underestimating internal threats, the cracks in the Corleone dynasty formed before anyone could comprehend the coming collapse.
What were the fatal mistakes that led to the downfall of this criminal icon?