Coxeter groups were introduced in the 1930s as abstractions of reflection groups. They appear in different areas of mathematics such as Lie theory, combinatorics, and geometric group theory. Any Coxeter group can be realised as the reflection group of a contractible complex, called the Davis complex. This talk focuses on a computation of the first three integral homology groups of an arbitrary Coxeter group using a spectral sequence argument: the answer can be phrased purely in terms of the original Coxeter diagram. I will give a gentle introduction to Coxeter groups and the Davis complex before outlining the proof.