The Geneva Conventions are a set of four treaties of international law at wartime. They were formulated in Geneva, Switzerland. All of the four treaties are about humanitarian issues. The Swiss Henri Dunant was the person who started the creation of the Conventions. He did this after he saw the unimaginable cruelty of the Battle of Solferino in 1859 and wrote a book about it.
Some parts of the four Geneva Conventions say that all countries who signed must create national laws to make violations of the Geneva Conventions a crime.