What is the past tense of the verb to be?

There are different kinds of past tenses in french. For example, the verb to be with " le passé simple" employed would be:

Je fus ( I was)

Tu fus  ( You were)

Il fut ( He was)

Nous fûmes ( We were)

Vous fûtes  ( You plural were)

Ils furents  ( They were)

Passe simple is used when you are referring to an action from the past, usually one that occured only for a short period of time. Today, le passe simple isn't used very often due to its very formal connotation.