Entente cordiale
The Entente cordiale (French for 'friendly agreement') was a number of agreements signed on 8 April 1904 between the United Kingdom and France. Both countries were worried that their growing empires would cause a war between them. The agreement was the end of almost 1000 years of frequent wars.
The agreement led to the Triple Entente (including Russia), which fought the Triple Alliance (Germany, Italy and Austria-Hungary) in the First World War and has lasted ever since. It was the start of the Triple Entente and the first step to stopping Germany from expanding. France had more chance with Britain of winning against Germany on the Western Front.