From Longman Dictionary of Contemporary Englishat your backat your backa) BEHINDbehind you They had the wind at their backs as they set off. b) supporting you Caesar marched into Rome with an army at his back. → back
Examples from the Corpus
at your back• She wants a phalanx of allies at her back before she climbs those stairs again.• Caesar marched into Rome with an army at his back.• The pub blazed at my back as I walked off.• She could tell this by looking at his back as he stood at the bar ordering more drinks.• When Schmidt tapped the chauffeur's arm, the man pressed a button that raised a glass panel at his back.• Run into the wind so it's at your back as you return.• She stared at his back view in exasperation.• Staring at his back, she tried to conjure up the image of him lover-like, tender, and failed.• I hear the whip at his back compelling him to shed his will, to stay in line.• He felt the wide gaze of the french windows at his back and the awareness put his timing out. 