The correct answer to this open question is the following.
England and France agreed to an alliance, called the Triple Entente.
We are talking about World War 1 years when France and Great Britain formed the Tripe Entente with Russia to fight against the Central Powers formed by Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria.
World War 1 started after the assassination of archduke Franz Ferdinand and his wife in Sarajevo. The war officially started in 1916 and ended in 1918.