Definition of the word join up

The phrase "join up" is an informal term that originated during World War I to describe the strategic alliance between Britain and France. The term "join up" refers to the military practice of bringing forces together to form a unified front against a common enemy. During the early stages of World War I in 1914, Britain and France were both involved in separate conflicts against Germany. However, as the war intensified and the destruction wrought by the German army became more apparent, there was a growing recognition of the need for these two allies to coordinate their military efforts in order to gain an advantage against the common enemy. The term "join up" gained widespread use after a meeting between the British Prime Minister, Herbert Henry Asquith, and the French President, Raymond Poincaré, in December 1915. During this meeting, the two leaders agreed to coordinate their military strategies more closely, laying the groundwork for the eventual creation of the Entente Cordiale, a diplomatic alliance between Britain and France that lasted well beyond the end of World War I. The term "join up" continues to be used more widely today to describe the practice of bringing together disparate entities or groups to form a united front, whether in military, political, or other contexts.