Galaxies are the basic unit of cosmology. The study of galaxy formation is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning. The physics of galaxy formation is complicated because it deals with the dynamics of stars, thermodynamics of gas and energy production of stars. A black hole is a massive object whose gravitational field is so intense that it prevents any form of matter or radiation to escape. It is hypothesised that the most massive galaxies in the universe -- "elliptical galaxies" -- grow simultaneously with the supermassive black holes at their centres, giving us much stronger evidence that black holes control galaxy formation. This book reviews new evidence in the field.