Did Hawking discover black holes or work out the principle of black holes?

Hawking worked out the principle of black holes and proved the existence of black holes with formulas.

The first black hole discovered by humans was X- 1 black hole. Its mass is about 10 times that of the sun, its diameter is about 60 kilometers (18 miles), and it is 8000 light years away from the earth. It is located in the constellation Cygnus. Black holes suck gas from the nearby blue Supergiant star. It spirals inward and releases huge heat, releasing high-energy X-rays and gamma rays.