Physics is full of such examples.

Newton’s theory of gravitation unified the motion of apples falling from a tree, cannonballs thrown into walls, the motion of planet earth around the sun, and even motion of all the known planetary bodies.

Electromagnetic waves gives us one understanding of X-rays, gamma radiation, visible light, infrared, radio waves, etc.

Quantum field theory unifies every microscopic theory of matter and energy we have ever known.

This list could be much longer.