I'm doing some research and need to know when basements/cellars came into existance. Can anyone tell me?

Question

I'm doing some research and need to know when basements/cellars came into existance. Can anyone tell me?

Answer 1

Neolithic people had storage pits which could qualify.  Underground chambers are widespread among early civilisations such as Egypt and Sumeria.  Some Triassic mammal-relatives (/Trirachdon/) were including food storage areas in their burrow systems over 240 million years ago.

I'll leave the definition of "basements / cellars" up to you.  At a guess, some houses have probably had storage space beneath them since about the first time people built houses.