Which force is most important in black hole formation?

Black holes form when gravity compresses matter so strongly that not even light can escape from inside the event horizon. This requires an extreme concentration of mass-energy, often produced by the collapse of massive stars or by the growth of supermassive black holes in galaxies. The other fundamental forces cannot stop the collapse once the gravity-driven conditions become severe enough. General relativity describes this process, though a complete quantum theory of black holes is still missing. Black holes are one of the clearest demonstrations of gravity’s power.