What was the name of the army group Britain sent to France to fight during the phony war?

The British army group sent to France during the Phoney War was known as the British Expeditionary Force (BEF). This force was deployed in September 1939 and consisted mainly of British and some Commonwealth troops. Their role was to support French forces against a potential German invasion, although active combat was limited during this period of relative inactivity on the Western Front.