Yes, while church history says so, I have looked for proof in
scripture. I found that proof in Romans ch 15 ! We all remember that
Paul was arrested in Jerusalem, then sent to Rome to be judged by
Caesar. However, sometime later, we read in Romans15
   24Whensoever I take my journey into Spain, I will come to you: for
I trust to see you in my journey, and to be brought on my way
thitherward by you, if first I be somewhat filled with your company.
   25But now I go unto Jerusalem to minister unto the saints.
   The only way this is possible is he had to have been released by
Caesar.   Paul was obviously arrested a few months to a year after
this letter was written  during the great persecution under Nero, then
beheaded. So yes, Romans is a series of Pauls letters compiled before
his death,  not just one letter.
   I was looking for this Bible scripture mention for several years
and it was just thursday evening  that the Holy Spirit showed me this!
 Thankyou, Lord!
Maranatha, Lewis