Hello pure in heart:
Try this thread from this Catholic Answers Forums: “Will The Real Successor of Peter Please Stand Up.”
forums.catholic-questions.org/showthread.php?t=41607&highlight=Linus
and these websites from the New Advent Catholic Encyclopedia:
newadvent.org/cathen/12272b.htm
newadvent.org/cathen/09272b.htm
Also, please remember that the word ‘Pope’ is derived from the Greek word ‘father’, and Catholics call their spiritual leaders ‘Father’ following Paul’s example: “I became your father in Jesus Christ through the Gospel” (1 Cor. 4:15).
The Pope is the Bishop of Rome, the Vicar of Christ, and the Patriarch of the West. And just as I would call any Catholic priest ‘Father’, I also call the head of the Church of Christ, father, i.e. Pope! It would be inappropriate to refer to any Catholic Priest as Pope, as it would be inappropriate to refer to any minister as Prime Minister or Senator as Mr. President.
Jesus appointed Peter as the head of the newly found universal church, a Bishop; and St. Linus was duly appointed Bishop in his turn.