The Fifty Bibles of Constantine were Bibles in Greek language commissioned in 331 by Constantine I and prepared by Eusebius of Caesarea. They were made for the use of the Bishop of Constantinople in the growing number of churches in that very new city. Eusebius quoted the letter of commission in his Life of Constantine, and it is the only surviving source from which we know of the existence of the Bibles.
According to Eusebius, Constantine 1 wrote him in his letter:
"I have thought it expedient to instruct your Prudence to order fifty copies of the sacred Scriptures, the provision and use of which you know to be most needful for the instruction of the Church, to be written on prepared parchment in a legible manner, and in a convenient, portable form, by professional transcribers thoroughly practised in their art."
About accomplishing the Emperor's demand:
They were to be
written on prepared parchment
The parchment of Siniaticus was white when originally found but after two months with Tischendorf it was tea colored as if stained by tea or coffee - the usual way of making pages look old in his days.. The pages originally send to Frederick the Great are still white and not old looking. This implies a young age for the manuscript and not a great age as Tischendorf seemed to imply.
in a legible manner,
There are many corrections in the codex and atg times you wonder what is the real text. It is not clearly legible with omissions and corrections and writing in different letters per line and sizes.
and in a convenient, portable form,
It is not readily portable unless you have a strong man being very large and heavy.
by professional transcribers thoroughly practiced in their art.
There are four or more editors of the codex all with different comments and styles so that it is obvious a scribe of excellent ability was not used to write the codex.
Does the Siniaticus meet these conditions?
It can be seen that the codex Siniaticus cannot be one ordered by Constantine but of a much later date so that all the hype about its age is false and may have been manufactured by Tischendorf.
Note that the way it and the Vaticanus are laid out indicates a date of writing after 444 AD
The Shepherd of Hermes document in the Siniaticus contains Greek words that do not exist in clasical Greek and were only used after the Middle ages so that this part of SIniaiticus cannot be more than a few hundred yers old, if even that