1
general::
Force to retreat or withdraw, as in His findings beat back all their arguments to the contrary. This phrase was often used in a military context (and still is), as in Their armies were beaten back. [Late 1500s]
American Heritage Idioms
2
general::
Phrase(s): beat someone or something back
to drive someone or something back to where it came from. • We beat them back to where they were before the war started. • The army beat back the defenders and saved the town. • They were able to beat the wolves back and make an escape.
McGrawhill's American Idioms And Phrasal Verbs