Four colour chess

Actually this post is not about 4 player chess, or multi coloured chess boards, but more about an historical link between the Four Color Theorem and chess. The Four Color Theorem states that you only need 4 colours to colour a map so that no region with a shared boundary (not corner) has the same colour. It is one of those maths problems which are easy to state, kind of simple to test, but difficult to prove.
One of the earliest (erroneous) proofs was given by Alfred Kempe, who was a mathematician and lawyer. He was also a pretty strong chess player, capable of pulling off some brilliant combinations. I came across a very good example where a slight slip by his opponent allowed a nice queen sacrifice, which led to the black king being caught in a mating net. Both perfectly sound, and delightfully 19th century.

Kempe,Alfred - S,G [C60]
Casual