Papal bulls, as official papal documents with a lead seal (bulla), have been used since

at least the 6th century CE

. However, the term "papal bull" didn't become official until the 15th century. Prior to that, the term was used internally for administrative purposes and wasn't widely applied to the documents themselves until the 13th century.

Here's a more detailed timeline:

• 6th Century Onward: Papal documents with lead seals (bullae) existed, but the term "papal bull" wasn't yet in use.

• 13th Century: The term "papal bull" began to be used, initially for internal administrative purposes and later for the documents themselves.

• 15th Century: The term became official, with one of the offices of the papal chancery being named the "register of bulls".

• 11th Century:

  Original papal bulls became more common after the transition from papyrus to parchment, which was more durable.