at the bottom of

at the bottom of

1. Covertly responsible for; being the real origin of.

   Synonym: behind

   I should have known you'd be at the bottom of all this!

   • 1844 January–December, W[illiam] M[akepeace] Thackeray, “My Pedigree and Family.—Undergo the Influence of the Tender Passion.”, in “The Memoirs of Barry Lyndon, Esq. [The Luck of Barry Lyndon.]”, in Miscellanies: Prose and Verse, volume III, London: Bradbury and Evans, […], published 1856, →OCLC, page 3:

     Since the days of Adam, there has been hardly a mischief done in this world but a woman has been at the bottom of it.

• at bottom