The Apocrypha as a Whole
The existence of an ‘Apocrypha’ arises mainly from the presence in one or more of the earliest Greek biblical codices (Alexandrinus, Sinaiticus, Vaticanus) of a number of books whose absence from the Jewish scriptural canon led Jerome to omit them at first from his translation into Latin (the Vulgate) as undeserving of canonical status. Subsequently he, or others, supplied translations from the Greek. The one complete exception is 2 Esdras/4 Ezra, which is in none of the ancient Greek Bibles, and the Prayer of Manasses constitutes a semi-exception, since it is not included in them as an independent book.
However, the contents of Latin Bibles have fluctuated over the centuries, and their contents did not necessarily correspond over time exactly to those of the Greek Bibles (which, in any case, did not preserve exactly the same list of books). Thus, it is not the case that the ‘Apocrypha’, effectively created as a category by Protestants, simply embraces those books in a Greek Bible but not a Hebrew one. However, that is effectively how the contents of the Apocrypha originated.
The books of the Apocrypha derive immediately from Greek texts. However, while in some cases Greek is the original language, in some a translation from another language is either known or suspected to have occurred. Even where Greek is the original language, we do not necessarily have only one Greek text form, let alone identical Greek texts, thanks to the process of continual copying and sometimes deliberate revision. Hence most of the books of the Apocrypha have an interesting textual history of their own, and it is therefore necessary to examine them individually.