I point you to any history of the Church, wherein Peter is always named as the first pope, though not a term or title which was used in the beginning.
St. Iranaeus, a disciple of Polycarp who was himself a disciple of St. John, first tracks the successions of the bishops of Rome.
St. Eusebius also does so.
I can’t remember who first uses the term “Apostolic Succession”.
Hearsay is not "... hard, factual, history which confirms Peter as Pope."