Meaning of the word "be at the bottom of" in English

What does "be at the bottom of" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

be at the bottom of

US /bi æt ðə ˈbɑtəm əv/
UK /bi æt ðə ˈbɒtəm əv/
"be at the bottom of" picture

Idiom

to be the real cause of something, especially something bad

Example:
I suspect he's at the bottom of this whole mess.
We need to find out who is at the bottom of these rumors.