What is the origin of the idiom "to the core" and when to use it?

The origin of the idiom "to the core" is not precisely known, but it has been in use for centuries in English. It is a versatile expression that can be applied to a wide range of situations and is commonly used in both spoken and written English and describe something or someone that is fundamentally or completely characterized by a particular quality, trait, or attribute. It suggests that the essence or innermost nature of the subject is deeply connected to that quality.