That's false. The Muslims won the Crusades.
Ivan III "the great" is the Ruler of Russia that defeated the Mongols. He tripled the territory of Russia under his rule and laid the foundations for the Russian state.
I believe the answer is: The builders of the Constitution ensured the extension of the principle of checks and balances.<span>
Because of this, they separate the government branches into 3, the legislative branch, the executive branch, and the judiciery.
Creating inferior courts is a way for the legislative branch of the government to checks and limit the power of the judiciery branch of the government.</span>
Neither side of the fight could advance due to the military prowess of the other